From 8ee59f0547a0c23dc5ac6ffc3e867ae2b06e030b Mon Sep 17 00:00:00 2001
From: Steffen Vogel <post@steffenvogel.de>
Date: Thu, 19 May 2022 17:40:10 +0200
Subject: [PATCH] relicense under Apache 2.0

---
 common/CMakeLists.txt                         |  14 +-
 common/COPYING.md                             | 869 ++++--------------
 common/Dockerfile                             |  16 +-
 common/README.md                              |  17 +-
 common/cmake/GetVersion.cmake                 |  16 +-
 common/include/villas/boxes.hpp               |  17 +-
 common/include/villas/buffer.hpp              |  17 +-
 common/include/villas/colors.hpp              |  17 +-
 common/include/villas/common.hpp              |  17 +-
 common/include/villas/compat.hpp              |  17 +-
 common/include/villas/config.hpp.in           |  17 +-
 common/include/villas/cpuset.hpp              |  17 +-
 .../include/villas/dsp/exponential_window.hpp |  17 +-
 .../villas/dsp/moving_average_window.hpp      |  17 +-
 common/include/villas/dsp/pid.hpp             |  17 +-
 common/include/villas/dsp/window.hpp          |  17 +-
 common/include/villas/dsp/window_cosine.hpp   |  17 +-
 common/include/villas/exceptions.hpp          |  17 +-
 common/include/villas/graph/directed.hpp      |  17 +-
 common/include/villas/graph/edge.hpp          |  17 +-
 common/include/villas/graph/vertex.hpp        |  17 +-
 common/include/villas/hist.hpp                |  17 +-
 common/include/villas/kernel/kernel.hpp       |  17 +-
 common/include/villas/kernel/pci.hpp          |  17 +-
 common/include/villas/kernel/rt.hpp           |  17 +-
 common/include/villas/list.hpp                |  15 +-
 common/include/villas/log.hpp                 |  17 +-
 common/include/villas/log_opal_sink.hpp       |  17 +-
 common/include/villas/memory.hpp              |  17 +-
 common/include/villas/memory_manager.hpp      |  17 +-
 common/include/villas/plugin.hpp              |  17 +-
 common/include/villas/popen.hpp               |  17 +-
 common/include/villas/table.hpp               |  17 +-
 common/include/villas/task.hpp                |  17 +-
 common/include/villas/terminal.hpp            |  17 +-
 common/include/villas/timing.hpp              |  17 +-
 common/include/villas/tool.hpp                |  17 +-
 common/include/villas/tsc.hpp                 |  17 +-
 common/include/villas/utils.hpp               |  17 +-
 common/include/villas/uuid.hpp                |  17 +-
 common/include/villas/version.hpp             |  17 +-
 common/lib/CMakeLists.txt                     |  14 +-
 common/lib/base64.cpp                         |  17 +-
 common/lib/buffer.cpp                         |  17 +-
 common/lib/common.cpp                         |  17 +-
 common/lib/compat.cpp                         |  17 +-
 common/lib/cpuset.cpp                         |  17 +-
 common/lib/dsp/pid.cpp                        |  17 +-
 common/lib/hist.cpp                           |  18 +-
 common/lib/kernel/kernel.cpp                  |  17 +-
 common/lib/kernel/pci.cpp                     |  17 +-
 common/lib/kernel/rt.cpp                      |  17 +-
 common/lib/kernel/vfio.cpp                    |  17 +-
 common/lib/list.cpp                           |  17 +-
 common/lib/log.cpp                            |  17 +-
 common/lib/memory.cpp                         |  17 +-
 common/lib/memory_manager.cpp                 |  17 +-
 common/lib/plugin.cpp                         |  17 +-
 common/lib/popen.cpp                          |  17 +-
 common/lib/table.cpp                          |  17 +-
 common/lib/task.cpp                           |  17 +-
 common/lib/terminal.cpp                       |  17 +-
 common/lib/timing.cpp                         |  17 +-
 common/lib/tool.cpp                           |  17 +-
 common/lib/tsc.cpp                            |  17 +-
 common/lib/utils.cpp                          |  17 +-
 common/lib/uuid.cpp                           |  17 +-
 common/lib/version.cpp                        |  17 +-
 common/tests/unit/CMakeLists.txt              |  14 +-
 common/tests/unit/base64.cpp                  |  17 +-
 common/tests/unit/buffer.cpp                  |  17 +-
 common/tests/unit/graph.cpp                   |  17 +-
 common/tests/unit/hist.cpp                    |  17 +-
 common/tests/unit/kernel.cpp                  |  17 +-
 common/tests/unit/list.cpp                    |  17 +-
 common/tests/unit/popen.cpp                   |  17 +-
 common/tests/unit/task.cpp                    |  17 +-
 common/tests/unit/timing.cpp                  |  17 +-
 common/tests/unit/tsc.cpp                     |  17 +-
 common/tests/unit/utils.cpp                   |  17 +-
 80 files changed, 275 insertions(+), 1925 deletions(-)

diff --git a/common/CMakeLists.txt b/common/CMakeLists.txt
index 2acaa98c8..1f6a1d46b 100644
--- a/common/CMakeLists.txt
+++ b/common/CMakeLists.txt
@@ -2,22 +2,10 @@
 #
 # @author Daniel Krebs <github@daniel-krebs.net>
 # @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
-# @license GNU General Public License (version 3)
+# @license Apache License 2.0
 #
 # VILLAScommon
 #
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ##############################################################################
 
 cmake_minimum_required(VERSION 3.7)
diff --git a/common/COPYING.md b/common/COPYING.md
index 2a99aeee3..d0af96c39 100644
--- a/common/COPYING.md
+++ b/common/COPYING.md
@@ -1,675 +1,194 @@
-### GNU GENERAL PUBLIC LICENSE
-
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-
-Copyright (C) 2007 Free Software Foundation, Inc.
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-or controlled by the contributor, whether already acquired or
-hereafter acquired, that would be infringed by some manner, permitted
-by this License, of making, using, or selling its contributor version,
-but do not include claims that would be infringed only as a
-consequence of further modification of the contributor version. For
-purposes of this definition, "control" includes the right to grant
-patent sublicenses in a manner consistent with the requirements of
-this License.
-
-Each contributor grants you a non-exclusive, worldwide, royalty-free
-patent license under the contributor's essential patent claims, to
-make, use, sell, offer for sale, import and otherwise run, modify and
-propagate the contents of its contributor version.
-
-In the following three paragraphs, a "patent license" is any express
-agreement or commitment, however denominated, not to enforce a patent
-(such as an express permission to practice a patent or covenant not to
-sue for patent infringement). To "grant" such a patent license to a
-party means to make such an agreement or commitment not to enforce a
-patent against the party.
-
-If you convey a covered work, knowingly relying on a patent license,
-and the Corresponding Source of the work is not available for anyone
-to copy, free of charge and under the terms of this License, through a
-publicly available network server or other readily accessible means,
-then you must either (1) cause the Corresponding Source to be so
-available, or (2) arrange to deprive yourself of the benefit of the
-patent license for this particular work, or (3) arrange, in a manner
-consistent with the requirements of this License, to extend the patent
-license to downstream recipients. "Knowingly relying" means you have
-actual knowledge that, but for the patent license, your conveying the
-covered work in a country, or your recipient's use of the covered work
-in a country, would infringe one or more identifiable patents in that
-country that you have reason to believe are valid.
-
-If, pursuant to or in connection with a single transaction or
-arrangement, you convey, or propagate by procuring conveyance of, a
-covered work, and grant a patent license to some of the parties
-receiving the covered work authorizing them to use, propagate, modify
-or convey a specific copy of the covered work, then the patent license
-you grant is automatically extended to all recipients of the covered
-work and works based on it.
-
-A patent license is "discriminatory" if it does not include within the
-scope of its coverage, prohibits the exercise of, or is conditioned on
-the non-exercise of one or more of the rights that are specifically
-granted under this License. You may not convey a covered work if you
-are a party to an arrangement with a third party that is in the
-business of distributing software, under which you make payment to the
-third party based on the extent of your activity of conveying the
-work, and under which the third party grants, to any of the parties
-who would receive the covered work from you, a discriminatory patent
-license (a) in connection with copies of the covered work conveyed by
-you (or copies made from those copies), or (b) primarily for and in
-connection with specific products or compilations that contain the
-covered work, unless you entered into that arrangement, or that patent
-license was granted, prior to 28 March 2007.
-
-Nothing in this License shall be construed as excluding or limiting
-any implied license or other defenses to infringement that may
-otherwise be available to you under applicable patent law.
-
-#### 12. No Surrender of Others' Freedom.
-
-If conditions are imposed on you (whether by court order, agreement or
-otherwise) that contradict the conditions of this License, they do not
-excuse you from the conditions of this License. If you cannot convey a
-covered work so as to satisfy simultaneously your obligations under
-this License and any other pertinent obligations, then as a
-consequence you may not convey it at all. For example, if you agree to
-terms that obligate you to collect a royalty for further conveying
-from those to whom you convey the Program, the only way you could
-satisfy both those terms and this License would be to refrain entirely
-from conveying the Program.
-
-#### 13. Use with the GNU Affero General Public License.
-
-Notwithstanding any other provision of this License, you have
-permission to link or combine any covered work with a work licensed
-under version 3 of the GNU Affero General Public License into a single
-combined work, and to convey the resulting work. The terms of this
-License will continue to apply to the part which is the covered work,
-but the special requirements of the GNU Affero General Public License,
-section 13, concerning interaction through a network will apply to the
-combination as such.
-
-#### 14. Revised Versions of this License.
-
-The Free Software Foundation may publish revised and/or new versions
-of the GNU General Public License from time to time. Such new versions
-will be similar in spirit to the present version, but may differ in
-detail to address new problems or concerns.
-
-Each version is given a distinguishing version number. If the Program
-specifies that a certain numbered version of the GNU General Public
-License "or any later version" applies to it, you have the option of
-following the terms and conditions either of that numbered version or
-of any later version published by the Free Software Foundation. If the
-Program does not specify a version number of the GNU General Public
-License, you may choose any version ever published by the Free
-Software Foundation.
-
-If the Program specifies that a proxy can decide which future versions
-of the GNU General Public License can be used, that proxy's public
-statement of acceptance of a version permanently authorizes you to
-choose that version for the Program.
-
-Later license versions may give you additional or different
-permissions. However, no additional obligations are imposed on any
-author or copyright holder as a result of your choosing to follow a
-later version.
-
-#### 15. Disclaimer of Warranty.
-
-THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
-APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
-HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT
-WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND
-PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE
-DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR
-CORRECTION.
-
-#### 16. Limitation of Liability.
-
-IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
-WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR
-CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
-INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES
-ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT
-NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR
-LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM
-TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER
-PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
-
-#### 17. Interpretation of Sections 15 and 16.
-
-If the disclaimer of warranty and limitation of liability provided
-above cannot be given local legal effect according to their terms,
-reviewing courts shall apply local law that most closely approximates
-an absolute waiver of all civil liability in connection with the
-Program, unless a warranty or assumption of liability accompanies a
-copy of the Program in return for a fee.
-
-END OF TERMS AND CONDITIONS
-
-### How to Apply These Terms to Your New Programs
-
-If you develop a new program, and you want it to be of the greatest
-possible use to the public, the best way to achieve this is to make it
-free software which everyone can redistribute and change under these
-terms.
-
-To do so, attach the following notices to the program. It is safest to
-attach them to the start of each source file to most effectively state
-the exclusion of warranty; and each file should have at least the
-"copyright" line and a pointer to where the full notice is found.
-
-        <one line to give the program's name and a brief idea of what it does.>
-        Copyright (C) <year>  <name of author>
-
-        This program is free software: you can redistribute it and/or modify
-        it under the terms of the GNU General Public License as published by
-        the Free Software Foundation, either version 3 of the License, or
-        (at your option) any later version.
-
-        This program is distributed in the hope that it will be useful,
-        but WITHOUT ANY WARRANTY; without even the implied warranty of
-        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-        GNU General Public License for more details.
-
-        You should have received a copy of the GNU General Public License
-        along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-Also add information on how to contact you by electronic and paper
-mail.
-
-If the program does terminal interaction, make it output a short
-notice like this when it starts in an interactive mode:
-
-        <program>  Copyright (C) <year>  <name of author>
-        This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
-        This is free software, and you are welcome to redistribute it
-        under certain conditions; type `show c' for details.
-
-The hypothetical commands \`show w' and \`show c' should show the
-appropriate parts of the General Public License. Of course, your
-program's commands might be different; for a GUI interface, you would
-use an "about box".
-
-You should also get your employer (if you work as a programmer) or
-school, if any, to sign a "copyright disclaimer" for the program, if
-necessary. For more information on this, and how to apply and follow
-the GNU GPL, see <http://www.gnu.org/licenses/>.
-
-The GNU General Public License does not permit incorporating your
-program into proprietary programs. If your program is a subroutine
-library, you may consider it more useful to permit linking proprietary
-applications with the library. If this is what you want to do, use the
-GNU Lesser General Public License instead of this License. But first,
-please read <http://www.gnu.org/philosophy/why-not-lgpl.html>.
\ No newline at end of file
+Apache License
+==============
+
+_Version 2.0, January 2004_  
+_&lt;<http://www.apache.org/licenses/>&gt;_
+
+### Terms and Conditions for use, reproduction, and distribution
+
+#### 1. Definitions
+
+“License” shall mean the terms and conditions for use, reproduction, and
+distribution as defined by Sections 1 through 9 of this document.
+
+“Licensor” shall mean the copyright owner or entity authorized by the copyright
+owner that is granting the License.
+
+“Legal Entity” shall mean the union of the acting entity and all other entities
+that control, are controlled by, or are under common control with that entity.
+For the purposes of this definition, “control” means **(i)** the power, direct or
+indirect, to cause the direction or management of such entity, whether by
+contract or otherwise, or **(ii)** ownership of fifty percent (50%) or more of the
+outstanding shares, or **(iii)** beneficial ownership of such entity.
+
+“You” (or “Your”) shall mean an individual or Legal Entity exercising
+permissions granted by this License.
+
+“Source” form shall mean the preferred form for making modifications, including
+but not limited to software source code, documentation source, and configuration
+files.
+
+“Object” form shall mean any form resulting from mechanical transformation or
+translation of a Source form, including but not limited to compiled object code,
+generated documentation, and conversions to other media types.
+
+“Work” shall mean the work of authorship, whether in Source or Object form, made
+available under the License, as indicated by a copyright notice that is included
+in or attached to the work (an example is provided in the Appendix below).
+
+“Derivative Works” shall mean any work, whether in Source or Object form, that
+is based on (or derived from) the Work and for which the editorial revisions,
+annotations, elaborations, or other modifications represent, as a whole, an
+original work of authorship. For the purposes of this License, Derivative Works
+shall not include works that remain separable from, or merely link (or bind by
+name) to the interfaces of, the Work and Derivative Works thereof.
+
+“Contribution” shall mean any work of authorship, including the original version
+of the Work and any modifications or additions to that Work or Derivative Works
+thereof, that is intentionally submitted to Licensor for inclusion in the Work
+by the copyright owner or by an individual or Legal Entity authorized to submit
+on behalf of the copyright owner. For the purposes of this definition,
+“submitted” means any form of electronic, verbal, or written communication sent
+to the Licensor or its representatives, including but not limited to
+communication on electronic mailing lists, source code control systems, and
+issue tracking systems that are managed by, or on behalf of, the Licensor for
+the purpose of discussing and improving the Work, but excluding communication
+that is conspicuously marked or otherwise designated in writing by the copyright
+owner as “Not a Contribution.”
+
+“Contributor” shall mean Licensor and any individual or Legal Entity on behalf
+of whom a Contribution has been received by Licensor and subsequently
+incorporated within the Work.
+
+#### 2. Grant of Copyright License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable copyright license to reproduce, prepare Derivative Works of,
+publicly display, publicly perform, sublicense, and distribute the Work and such
+Derivative Works in Source or Object form.
+
+#### 3. Grant of Patent License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable (except as stated in this section) patent license to make, have
+made, use, offer to sell, sell, import, and otherwise transfer the Work, where
+such license applies only to those patent claims licensable by such Contributor
+that are necessarily infringed by their Contribution(s) alone or by combination
+of their Contribution(s) with the Work to which such Contribution(s) was
+submitted. If You institute patent litigation against any entity (including a
+cross-claim or counterclaim in a lawsuit) alleging that the Work or a
+Contribution incorporated within the Work constitutes direct or contributory
+patent infringement, then any patent licenses granted to You under this License
+for that Work shall terminate as of the date such litigation is filed.
+
+#### 4. Redistribution
+
+You may reproduce and distribute copies of the Work or Derivative Works thereof
+in any medium, with or without modifications, and in Source or Object form,
+provided that You meet the following conditions:
+
+* **(a)** You must give any other recipients of the Work or Derivative Works a copy of
+this License; and
+* **(b)** You must cause any modified files to carry prominent notices stating that You
+changed the files; and
+* **(c)** You must retain, in the Source form of any Derivative Works that You distribute,
+all copyright, patent, trademark, and attribution notices from the Source form
+of the Work, excluding those notices that do not pertain to any part of the
+Derivative Works; and
+* **(d)** If the Work includes a “NOTICE” text file as part of its distribution, then any
+Derivative Works that You distribute must include a readable copy of the
+attribution notices contained within such NOTICE file, excluding those notices
+that do not pertain to any part of the Derivative Works, in at least one of the
+following places: within a NOTICE text file distributed as part of the
+Derivative Works; within the Source form or documentation, if provided along
+with the Derivative Works; or, within a display generated by the Derivative
+Works, if and wherever such third-party notices normally appear. The contents of
+the NOTICE file are for informational purposes only and do not modify the
+License. You may add Your own attribution notices within Derivative Works that
+You distribute, alongside or as an addendum to the NOTICE text from the Work,
+provided that such additional attribution notices cannot be construed as
+modifying the License.
+
+You may add Your own copyright statement to Your modifications and may provide
+additional or different license terms and conditions for use, reproduction, or
+distribution of Your modifications, or for any such Derivative Works as a whole,
+provided Your use, reproduction, and distribution of the Work otherwise complies
+with the conditions stated in this License.
+
+#### 5. Submission of Contributions
+
+Unless You explicitly state otherwise, any Contribution intentionally submitted
+for inclusion in the Work by You to the Licensor shall be under the terms and
+conditions of this License, without any additional terms or conditions.
+Notwithstanding the above, nothing herein shall supersede or modify the terms of
+any separate license agreement you may have executed with Licensor regarding
+such Contributions.
+
+#### 6. Trademarks
+
+This License does not grant permission to use the trade names, trademarks,
+service marks, or product names of the Licensor, except as required for
+reasonable and customary use in describing the origin of the Work and
+reproducing the content of the NOTICE file.
+
+#### 7. Disclaimer of Warranty
+
+Unless required by applicable law or agreed to in writing, Licensor provides the
+Work (and each Contributor provides its Contributions) on an “AS IS” BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
+including, without limitation, any warranties or conditions of TITLE,
+NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are
+solely responsible for determining the appropriateness of using or
+redistributing the Work and assume any risks associated with Your exercise of
+permissions under this License.
+
+#### 8. Limitation of Liability
+
+In no event and under no legal theory, whether in tort (including negligence),
+contract, or otherwise, unless required by applicable law (such as deliberate
+and grossly negligent acts) or agreed to in writing, shall any Contributor be
+liable to You for damages, including any direct, indirect, special, incidental,
+or consequential damages of any character arising as a result of this License or
+out of the use or inability to use the Work (including but not limited to
+damages for loss of goodwill, work stoppage, computer failure or malfunction, or
+any and all other commercial damages or losses), even if such Contributor has
+been advised of the possibility of such damages.
+
+#### 9. Accepting Warranty or Additional Liability
+
+While redistributing the Work or Derivative Works thereof, You may choose to
+offer, and charge a fee for, acceptance of support, warranty, indemnity, or
+other liability obligations and/or rights consistent with this License. However,
+in accepting such obligations, You may act only on Your own behalf and on Your
+sole responsibility, not on behalf of any other Contributor, and only if You
+agree to indemnify, defend, and hold each Contributor harmless for any liability
+incurred by, or claims asserted against, such Contributor by reason of your
+accepting any such warranty or additional liability.
+
+_END OF TERMS AND CONDITIONS_
+
+### APPENDIX: How to apply the Apache License to your work
+
+To apply the Apache License to your work, attach the following boilerplate
+notice, with the fields enclosed by brackets `[]` replaced with your own
+identifying information. (Don't include the brackets!) The text should be
+enclosed in the appropriate comment syntax for the file format. We also
+recommend that a file or class name and description of purpose be included on
+the same “printed page” as the copyright notice for easier identification within
+third-party archives.
+
+    Copyright [yyyy] [name of copyright owner]
+    
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+    
+      http://www.apache.org/licenses/LICENSE-2.0
+    
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
diff --git a/common/Dockerfile b/common/Dockerfile
index a2e414028..b1f10275d 100644
--- a/common/Dockerfile
+++ b/common/Dockerfile
@@ -10,22 +10,10 @@
 #
 # @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
 # @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
-# @license GNU General Public License (version 3)
+# @license Apache License 2.0
 #
 # VILLAScommon
 #
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ###################################################################################
 
 FROM fedora:33
@@ -33,7 +21,7 @@ FROM fedora:33
 LABEL \
 	org.label-schema.schema-version="1.0" \
 	org.label-schema.name="VILLAScommon" \
-	org.label-schema.license="GPL-3.0" \
+	org.label-schema.license="Apache-2.0" \
 	org.label-schema.vendor="Institute for Automation of Complex Power Systems, RWTH Aachen University" \
 	org.label-schema.author.name="Steffen Vogel" \
 	org.label-schema.author.email="svogel2@eonerc.rwth-aachen.de" \
diff --git a/common/README.md b/common/README.md
index 41c07c6a7..403e4783e 100644
--- a/common/README.md
+++ b/common/README.md
@@ -14,22 +14,7 @@ User documentation is available here: <https://villas.fein-aachen.org/doc/>
 
 ## License
 
-This project is released under the terms of the [GPL version 3](COPYING.md).
-
-```
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-```
+This project is released under the terms of the [Apache 2.0 license](COPYING.md).
 
 For other licensing options please consult [Prof. Antonello Monti](mailto:amonti@eonerc.rwth-aachen.de).
 
diff --git a/common/cmake/GetVersion.cmake b/common/cmake/GetVersion.cmake
index 1820b4640..d87b273cb 100644
--- a/common/cmake/GetVersion.cmake
+++ b/common/cmake/GetVersion.cmake
@@ -2,22 +2,10 @@
 #
 # @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
 # @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
-# @license GNU General Public License (version 3)
+# @license Apache License 2.0
 #
 # VILLASnode
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 ###################################################################################
 
 # This CMake function sets the following variables:
diff --git a/common/include/villas/boxes.hpp b/common/include/villas/boxes.hpp
index 312cae28f..05ad3c618 100644
--- a/common/include/villas/boxes.hpp
+++ b/common/include/villas/boxes.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLASnode
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/buffer.hpp b/common/include/villas/buffer.hpp
index bbf093b80..763c2ba28 100644
--- a/common/include/villas/buffer.hpp
+++ b/common/include/villas/buffer.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/colors.hpp b/common/include/villas/colors.hpp
index a292c4843..5e2cdb6af 100644
--- a/common/include/villas/colors.hpp
+++ b/common/include/villas/colors.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2017, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLASnode
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/common.hpp b/common/include/villas/common.hpp
index 30879582f..b18bf1088 100644
--- a/common/include/villas/common.hpp
+++ b/common/include/villas/common.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/compat.hpp b/common/include/villas/compat.hpp
index b68f57a55..6b97b742c 100644
--- a/common/include/villas/compat.hpp
+++ b/common/include/villas/compat.hpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/config.hpp.in b/common/include/villas/config.hpp.in
index af2a0f72f..1bb5c3a89 100644
--- a/common/include/villas/config.hpp.in
+++ b/common/include/villas/config.hpp.in
@@ -6,22 +6,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/cpuset.hpp b/common/include/villas/cpuset.hpp
index 81588ff1f..89f2dd80a 100644
--- a/common/include/villas/cpuset.hpp
+++ b/common/include/villas/cpuset.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/dsp/exponential_window.hpp b/common/include/villas/dsp/exponential_window.hpp
index 400636d56..21eec81da 100644
--- a/common/include/villas/dsp/exponential_window.hpp
+++ b/common/include/villas/dsp/exponential_window.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/dsp/moving_average_window.hpp b/common/include/villas/dsp/moving_average_window.hpp
index 4e9a76efd..03031516f 100644
--- a/common/include/villas/dsp/moving_average_window.hpp
+++ b/common/include/villas/dsp/moving_average_window.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/dsp/pid.hpp b/common/include/villas/dsp/pid.hpp
index b7413a3a5..e3f34a147 100644
--- a/common/include/villas/dsp/pid.hpp
+++ b/common/include/villas/dsp/pid.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/dsp/window.hpp b/common/include/villas/dsp/window.hpp
index a997dd896..be1ca383a 100644
--- a/common/include/villas/dsp/window.hpp
+++ b/common/include/villas/dsp/window.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/dsp/window_cosine.hpp b/common/include/villas/dsp/window_cosine.hpp
index 5571b896f..85a6f1f8c 100644
--- a/common/include/villas/dsp/window_cosine.hpp
+++ b/common/include/villas/dsp/window_cosine.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/exceptions.hpp b/common/include/villas/exceptions.hpp
index c36f6bb41..da4bfb7ac 100644
--- a/common/include/villas/exceptions.hpp
+++ b/common/include/villas/exceptions.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLASnode
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/graph/directed.hpp b/common/include/villas/graph/directed.hpp
index 1f2fadc7d..cd75102dd 100644
--- a/common/include/villas/graph/directed.hpp
+++ b/common/include/villas/graph/directed.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Daniel Krebs <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/graph/edge.hpp b/common/include/villas/graph/edge.hpp
index 475823621..86b7e24e7 100644
--- a/common/include/villas/graph/edge.hpp
+++ b/common/include/villas/graph/edge.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Daniel Krebs <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/graph/vertex.hpp b/common/include/villas/graph/vertex.hpp
index 988bbb9c0..75b04d782 100644
--- a/common/include/villas/graph/vertex.hpp
+++ b/common/include/villas/graph/vertex.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Daniel Krebs <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/hist.hpp b/common/include/villas/hist.hpp
index 2f589af2e..f9a84b732 100644
--- a/common/include/villas/hist.hpp
+++ b/common/include/villas/hist.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/kernel/kernel.hpp b/common/include/villas/kernel/kernel.hpp
index 86989aa1c..87f810cbc 100644
--- a/common/include/villas/kernel/kernel.hpp
+++ b/common/include/villas/kernel/kernel.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/kernel/pci.hpp b/common/include/villas/kernel/pci.hpp
index 97fb02573..82a91a622 100644
--- a/common/include/villas/kernel/pci.hpp
+++ b/common/include/villas/kernel/pci.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/kernel/rt.hpp b/common/include/villas/kernel/rt.hpp
index d9d876d67..e4aa96dc5 100644
--- a/common/include/villas/kernel/rt.hpp
+++ b/common/include/villas/kernel/rt.hpp
@@ -4,22 +4,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/list.hpp b/common/include/villas/list.hpp
index 22bfabf09..6c4e9ee68 100644
--- a/common/include/villas/list.hpp
+++ b/common/include/villas/list.hpp
@@ -11,20 +11,7 @@
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
 *
  * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *********************************************************************************/
+ * *********************************************************************************/
 
 #pragma once
 
diff --git a/common/include/villas/log.hpp b/common/include/villas/log.hpp
index 333f7899b..855ae1341 100644
--- a/common/include/villas/log.hpp
+++ b/common/include/villas/log.hpp
@@ -4,22 +4,7 @@
  * @author Daniel Krebs <github@daniel-krebs.net>
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/log_opal_sink.hpp b/common/include/villas/log_opal_sink.hpp
index cc9d9320b..6aa052cdc 100644
--- a/common/include/villas/log_opal_sink.hpp
+++ b/common/include/villas/log_opal_sink.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/memory.hpp b/common/include/villas/memory.hpp
index ebe86d91d..df61cec70 100644
--- a/common/include/villas/memory.hpp
+++ b/common/include/villas/memory.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Daniel Krebs <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/memory_manager.hpp b/common/include/villas/memory_manager.hpp
index b76e08623..8337a7b1f 100644
--- a/common/include/villas/memory_manager.hpp
+++ b/common/include/villas/memory_manager.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Daniel Krebs <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/plugin.hpp b/common/include/villas/plugin.hpp
index b4173eddb..d87291b95 100644
--- a/common/include/villas/plugin.hpp
+++ b/common/include/villas/plugin.hpp
@@ -4,22 +4,7 @@
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @author Daniel Krebs <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/popen.hpp b/common/include/villas/popen.hpp
index 5301c1065..fcd16a136 100644
--- a/common/include/villas/popen.hpp
+++ b/common/include/villas/popen.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/table.hpp b/common/include/villas/table.hpp
index 400fb1cea..0a8e3505d 100644
--- a/common/include/villas/table.hpp
+++ b/common/include/villas/table.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/task.hpp b/common/include/villas/task.hpp
index 20585787c..e21fefe79 100644
--- a/common/include/villas/task.hpp
+++ b/common/include/villas/task.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/terminal.hpp b/common/include/villas/terminal.hpp
index cb2a58f66..f4f612272 100644
--- a/common/include/villas/terminal.hpp
+++ b/common/include/villas/terminal.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/timing.hpp b/common/include/villas/timing.hpp
index 50c602acf..9a149f48e 100644
--- a/common/include/villas/timing.hpp
+++ b/common/include/villas/timing.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/tool.hpp b/common/include/villas/tool.hpp
index f4f410d5a..dfb263298 100644
--- a/common/include/villas/tool.hpp
+++ b/common/include/villas/tool.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLASnode
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/tsc.hpp b/common/include/villas/tsc.hpp
index c94a8d5b2..455a2a7a0 100644
--- a/common/include/villas/tsc.hpp
+++ b/common/include/villas/tsc.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/utils.hpp b/common/include/villas/utils.hpp
index 08430bd67..49c422258 100644
--- a/common/include/villas/utils.hpp
+++ b/common/include/villas/utils.hpp
@@ -4,22 +4,7 @@
  * @author Steffen Vogel <github@daniel-krebs.net>
  * @author Daniel Krebs <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/uuid.hpp b/common/include/villas/uuid.hpp
index b8d12a50b..bd5ac4020 100644
--- a/common/include/villas/uuid.hpp
+++ b/common/include/villas/uuid.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/include/villas/version.hpp b/common/include/villas/version.hpp
index 4c4939030..e375406ca 100644
--- a/common/include/villas/version.hpp
+++ b/common/include/villas/version.hpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #pragma once
diff --git a/common/lib/CMakeLists.txt b/common/lib/CMakeLists.txt
index 693ccaf0c..91163f0c7 100644
--- a/common/lib/CMakeLists.txt
+++ b/common/lib/CMakeLists.txt
@@ -2,22 +2,10 @@
 #
 # @author Daniel Krebs <github@daniel-krebs.net>
 # @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
-# @license GNU General Public License (version 3)
+# @license Apache License 2.0
 #
 # VILLAScommon
 #
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ##############################################################################
 
 add_library(villas-common SHARED
diff --git a/common/lib/base64.cpp b/common/lib/base64.cpp
index 7348bc355..8e8a29c98 100644
--- a/common/lib/base64.cpp
+++ b/common/lib/base64.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <string>
diff --git a/common/lib/buffer.cpp b/common/lib/buffer.cpp
index a39d67918..6527c5212 100644
--- a/common/lib/buffer.cpp
+++ b/common/lib/buffer.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <villas/compat.hpp>
diff --git a/common/lib/common.cpp b/common/lib/common.cpp
index 9afec96b5..f6feb8776 100644
--- a/common/lib/common.cpp
+++ b/common/lib/common.cpp
@@ -3,22 +3,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLASnode
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <villas/common.hpp>
diff --git a/common/lib/compat.cpp b/common/lib/compat.cpp
index 46874491d..63f0e14dc 100644
--- a/common/lib/compat.cpp
+++ b/common/lib/compat.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <cstring>
diff --git a/common/lib/cpuset.cpp b/common/lib/cpuset.cpp
index b21ba7bdd..748de34e2 100644
--- a/common/lib/cpuset.cpp
+++ b/common/lib/cpuset.cpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <villas/cpuset.hpp>
diff --git a/common/lib/dsp/pid.cpp b/common/lib/dsp/pid.cpp
index 86a54f89e..f73bc1e0a 100644
--- a/common/lib/dsp/pid.cpp
+++ b/common/lib/dsp/pid.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <iostream>
diff --git a/common/lib/hist.cpp b/common/lib/hist.cpp
index 4f0727a6b..15c6eefe2 100644
--- a/common/lib/hist.cpp
+++ b/common/lib/hist.cpp
@@ -2,27 +2,11 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <cmath>
 #include <algorithm>
-#include <cfloat> // for DBL_MAX
 
 #include <villas/utils.hpp>
 #include <villas/hist.hpp>
diff --git a/common/lib/kernel/kernel.cpp b/common/lib/kernel/kernel.cpp
index b650e39c7..eb8903928 100644
--- a/common/lib/kernel/kernel.cpp
+++ b/common/lib/kernel/kernel.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <sys/utsname.h>
diff --git a/common/lib/kernel/pci.cpp b/common/lib/kernel/pci.cpp
index afb3b087d..63cb4457e 100644
--- a/common/lib/kernel/pci.cpp
+++ b/common/lib/kernel/pci.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <dirent.h>
diff --git a/common/lib/kernel/rt.cpp b/common/lib/kernel/rt.cpp
index ff2cd45e4..a9207c495 100644
--- a/common/lib/kernel/rt.cpp
+++ b/common/lib/kernel/rt.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <sched.h>
diff --git a/common/lib/kernel/vfio.cpp b/common/lib/kernel/vfio.cpp
index 780702dd6..cc4e68d04 100644
--- a/common/lib/kernel/vfio.cpp
+++ b/common/lib/kernel/vfio.cpp
@@ -4,22 +4,7 @@
  * @author Daniel Krebs <github@daniel-krebs.net>
  * @copyright 2014-2021, Steffen Vogel
  * @copyright 2018, Daniel Krebs
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #define _DEFAULT_SOURCE
diff --git a/common/lib/list.cpp b/common/lib/list.cpp
index 173963b7e..b24d0c051 100644
--- a/common/lib/list.cpp
+++ b/common/lib/list.cpp
@@ -4,22 +4,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <array>
diff --git a/common/lib/log.cpp b/common/lib/log.cpp
index 8f9bb158c..06bc8c78d 100644
--- a/common/lib/log.cpp
+++ b/common/lib/log.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <list>
diff --git a/common/lib/memory.cpp b/common/lib/memory.cpp
index f37c19ca8..17954d671 100644
--- a/common/lib/memory.cpp
+++ b/common/lib/memory.cpp
@@ -2,22 +2,7 @@
  *
  * @author Daniel Krebs <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <sys/mman.h>
diff --git a/common/lib/memory_manager.cpp b/common/lib/memory_manager.cpp
index fe33cf964..6d2d3e599 100644
--- a/common/lib/memory_manager.cpp
+++ b/common/lib/memory_manager.cpp
@@ -2,22 +2,7 @@
  *
  * @author Daniel Krebs <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <memory>
diff --git a/common/lib/plugin.cpp b/common/lib/plugin.cpp
index 05f51eebd..b1e469f61 100644
--- a/common/lib/plugin.cpp
+++ b/common/lib/plugin.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <iostream>
diff --git a/common/lib/popen.cpp b/common/lib/popen.cpp
index 2753c5a58..341178807 100644
--- a/common/lib/popen.cpp
+++ b/common/lib/popen.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <sys/types.h>
diff --git a/common/lib/table.cpp b/common/lib/table.cpp
index eaabcd952..31c7d32e8 100644
--- a/common/lib/table.cpp
+++ b/common/lib/table.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <cstdlib>
diff --git a/common/lib/task.cpp b/common/lib/task.cpp
index 9a0c876a0..dd5d24607 100644
--- a/common/lib/task.cpp
+++ b/common/lib/task.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <unistd.h>
diff --git a/common/lib/terminal.cpp b/common/lib/terminal.cpp
index 12e8b723b..4954ba4bb 100644
--- a/common/lib/terminal.cpp
+++ b/common/lib/terminal.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <unistd.h>
diff --git a/common/lib/timing.cpp b/common/lib/timing.cpp
index 25fec99c0..88d4b12b7 100644
--- a/common/lib/timing.cpp
+++ b/common/lib/timing.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <unistd.h>
diff --git a/common/lib/tool.cpp b/common/lib/tool.cpp
index bfc375d69..02f795ae9 100644
--- a/common/lib/tool.cpp
+++ b/common/lib/tool.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLASnode
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <iostream>
diff --git a/common/lib/tsc.cpp b/common/lib/tsc.cpp
index 1f4913d0d..d823e80cd 100644
--- a/common/lib/tsc.cpp
+++ b/common/lib/tsc.cpp
@@ -3,22 +3,7 @@
  * @file
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <villas/tsc.hpp>
diff --git a/common/lib/utils.cpp b/common/lib/utils.cpp
index 6bd70710a..0110e17e9 100644
--- a/common/lib/utils.cpp
+++ b/common/lib/utils.cpp
@@ -3,22 +3,7 @@
  * @author Daniel Krebs <github@daniel-krebs.net>
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <vector>
diff --git a/common/lib/uuid.cpp b/common/lib/uuid.cpp
index 6675e9490..0d7750c65 100644
--- a/common/lib/uuid.cpp
+++ b/common/lib/uuid.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <openssl/md5.h>
diff --git a/common/lib/version.cpp b/common/lib/version.cpp
index a788d93b0..20cb2f0c2 100644
--- a/common/lib/version.cpp
+++ b/common/lib/version.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <github@daniel-krebs.net>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <stdexcept>
diff --git a/common/tests/unit/CMakeLists.txt b/common/tests/unit/CMakeLists.txt
index 3e80fad00..5fcebd050 100644
--- a/common/tests/unit/CMakeLists.txt
+++ b/common/tests/unit/CMakeLists.txt
@@ -2,22 +2,10 @@
 #
 # @author Daniel Krebs <github@daniel-krebs.net>
 # @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
-# @license GNU General Public License (version 3)
+# @license Apache License 2.0
 #
 # VILLAScommon
 #
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ##############################################################################
 
 add_executable(unit-tests-common
diff --git a/common/tests/unit/base64.cpp b/common/tests/unit/base64.cpp
index 27d9ecdf0..74ce205d2 100644
--- a/common/tests/unit/base64.cpp
+++ b/common/tests/unit/base64.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <criterion/criterion.h>
diff --git a/common/tests/unit/buffer.cpp b/common/tests/unit/buffer.cpp
index e5a7e0f76..e8cdddd32 100644
--- a/common/tests/unit/buffer.cpp
+++ b/common/tests/unit/buffer.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <cstdlib>
diff --git a/common/tests/unit/graph.cpp b/common/tests/unit/graph.cpp
index be3c6deee..e284232f3 100644
--- a/common/tests/unit/graph.cpp
+++ b/common/tests/unit/graph.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2021, Steffen Vogel
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <memory>
diff --git a/common/tests/unit/hist.cpp b/common/tests/unit/hist.cpp
index aabf63b0b..6dfa07bf8 100644
--- a/common/tests/unit/hist.cpp
+++ b/common/tests/unit/hist.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <array>
diff --git a/common/tests/unit/kernel.cpp b/common/tests/unit/kernel.cpp
index ca2c34196..20b34a19b 100644
--- a/common/tests/unit/kernel.cpp
+++ b/common/tests/unit/kernel.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <criterion/criterion.h>
diff --git a/common/tests/unit/list.cpp b/common/tests/unit/list.cpp
index b367b0d5e..6ca5db839 100644
--- a/common/tests/unit/list.cpp
+++ b/common/tests/unit/list.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <cstdint>
diff --git a/common/tests/unit/popen.cpp b/common/tests/unit/popen.cpp
index 7263318d6..699113ed3 100644
--- a/common/tests/unit/popen.cpp
+++ b/common/tests/unit/popen.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <iostream>
diff --git a/common/tests/unit/task.cpp b/common/tests/unit/task.cpp
index 66c286840..82f0dc3c1 100644
--- a/common/tests/unit/task.cpp
+++ b/common/tests/unit/task.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <criterion/criterion.h>
diff --git a/common/tests/unit/timing.cpp b/common/tests/unit/timing.cpp
index 585a985eb..1defa065f 100644
--- a/common/tests/unit/timing.cpp
+++ b/common/tests/unit/timing.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <unistd.h>
diff --git a/common/tests/unit/tsc.cpp b/common/tests/unit/tsc.cpp
index 7b6c91f40..c777ffa95 100644
--- a/common/tests/unit/tsc.cpp
+++ b/common/tests/unit/tsc.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <criterion/criterion.h>
diff --git a/common/tests/unit/utils.cpp b/common/tests/unit/utils.cpp
index 2a7553fc0..9967c00fa 100644
--- a/common/tests/unit/utils.cpp
+++ b/common/tests/unit/utils.cpp
@@ -2,22 +2,7 @@
  *
  * @author Steffen Vogel <svogel2@eonerc.rwth-aachen.de>
  * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
- * @license GNU General Public License (version 3)
- *
- * VILLAScommon
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * @license Apache License 2.0
  *********************************************************************************/
 
 #include <criterion/criterion.h>