This document outlines the licensing policy for the Polypheny Project, which is distributed under the Apache License, Version 2.0 (the “License”). This policy explains which licenses for dependencies are acceptable within the project. The purpose of this policy is to maintain the project’s open and free status, as well as its compatibility with other open source software.
Licensing in the Polypheny Project
The Polypheny Project is predominantly licensed under the Apache License, Version 2.0. A copy of this License is accessible within the LICENSE file found in our code repository. Alternatively, a copy can be obtained from the Apache Software Foundation.
However, certain components of the project stack, most notably the browser-based user interface known as Polypheny-UI, are distributed under the MIT License. A copy of this license can also be found within the respective LICENSE file in the code repository.
We stand firm in our belief in open-source software and strive to release as much of the project stack under open-source licenses as possible. Nonetheless, please be aware that some components, primarily those specifically tailored for enterprise usage, may not be available under an open-source license due to various reasons. We seek your understanding in these matters as we continue to promote openness and collaboration in the majority of our work.
Acceptable Licenses for Dependencies
Dependencies are libraries or modules that our project relies on to provide its functionality. These dependencies may come with their own licenses. The following conditions must be met for a license of a dependency to be acceptable in the Polypheny Project:
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License Compatibility: The license of the dependency must be compatible with the Apache License, Version 2.0. This typically includes permissive licenses such as the MIT License, the BSD 2-clause and 3-clause licenses, and other versions of the Apache License.
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Open Source: The license of the dependency should be recognized as an open source license by the Open Source Initiative (OSI). This ensures that the dependency’s code is freely available and modifiable.
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No Copyleft: The license must not be a “copyleft” or “viral” license. These licenses (such as the GPL and AGPL) require that derivative works also be open-sourced under the same license, which could place additional restrictions on the use of Polypheny.
Here is a non-exhaustive list of acceptable licenses for dependencies within the Polypheny project:
- Apache License 2.0
- Apache Software License 1.1, including variants:
- PHP License 3.01
- MX4J License
- BSD (without advertising clause), including variants:
- BSD 2-clause
- BSD 3-clause
- DOM4J License
- PostgreSQL License
- Eclipse Distribution License 1.0
- MIT/X11, including variants:
- ISC
- Cup Parser Generator
- ICU
- W3C Software License
- Academic Free License 3.0
- Microsoft Public License (MsPL)
- Creative Commons Copyright-Only Dedication
- Python Software Foundation License
- WTF Public License
- The Romantic WTF public license
- The Unlicense
Note that while these licenses are generally accepted, any potential contributors should verify the license of a new dependency prior to its integration into the Polypheny Project. Please do not hesitate to contact a maintainer for assistance if needed.
Unacceptable Licenses for Dependencies
Any license not meeting the conditions above is considered unacceptable for the Polypheny Project. This includes but is not limited to:
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Non-Open Source Licenses: Licenses not recognized as open source by the OSI.
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Copyleft Licenses: Licenses that require derivative works to be open-sourced under the same license (e.g., GPL, AGPL, LGPL).
Here is a non-exhaustive list of licenses for dependencies that may NOT be used in the Polypheny project:
- Amazon Software License (ASL): This license has specific terms that restrict commercial usage and distribution, making it incompatible with the Apache License 2.0.
- Any license including the Commons Clause License Condition v1.0: This clause restricts selling of the software, making it non-free and incompatible with the Apache License 2.0.
- Binary Code License (BCL): This license is often used by Oracle for its Java platform. It doesn’t grant the same freedom of use as open source licenses and isn’t compatible with the Apache License 2.0.
- BSD-4-Clause/BSD-4-Clause (University of California-Specific): This license includes a clause endorsing the University of California, which is incompatible with the Apache License 2.0.
- Creative Commons Non-Commercial variants: These licenses restrict commercial use, which is incompatible with the principles of free and open-source software.
- Facebook BSD+Patents license: This license includes a patent retaliation clause which is deemed problematic and incompatible with the Apache License 2.0.
- GNU Affero GPL 3: This is a copyleft license similar to the GPL but with additional requirements related to network usage.
- GNU GPL 1, 2, 3: The GPL licenses are copyleft licenses, which require derivative works to be open-sourced under the same license, a requirement that is incompatible with the Apache License 2.0.
- GNU LGPL 2, 2.1, 3: While more permissive than the GPL, the LGPL still contains copyleft provisions that are incompatible with the Apache License 2.0.
- Intel Simplified Software License: This license is not recognized by the Open Source Initiative (OSI) and lacks an explicit patent grant clause.
- JSR-275 License: This license is not OSI-approved and has restrictions that are incompatible with the Apache License 2.0.
- Microsoft Limited Public License: This is a non-free, source-available license that has restrictions on commercial use.
- NPL 1.0/NPL 1.1: The Netscape Public Licenses are not recognized as open source licenses by the OSI.
- Redis Source Available License (RSAL): This is a source-available license, not an open source license, with limitations on usage for certain services, particularly database products or services.
- Server Side Public License (SSPL) version 1: This license has strong copyleft provisions related to providing services over a network, which is incompatible with the Apache License 2.0.
- Sun Community Source License 3.0: This license includes additional requirements and restrictions not compatible with the Apache License 2.0.
- The “Don’t Be A Dick” Public License: This license is not recognized by the OSI and contains subjective terms that are incompatible with the principles of free and open-source software.
- The Solipsistic Eclipse Public License: This license is not recognized by the OSI and its terms can conflict with the Apache License 2.0.
- JSON License: This license includes the clause “The Software shall be used for Good, not Evil”, which is subjective, undefined, and thus incompatible with the principles of free and open-source software.
Remember, this list is not exhaustive and there might be other reasons why a particular license is not compatible with our license policy. Please do not hesitate to contact a maintainer for assistance if needed.
