Open Source Licenses

Navigating the Fascinating Landscape of Android Open Source Licenses

Android Open Source licenses constitute the legal framework that governs the use, distribution, and modification of open-source software. There's a myriad of licenses, each with specific conditions and permissions, designed to protect the interests of contributors while fostering a collaborative development environment. Key licenses include the MIT License, allowing almost limitless modification and distribution, and the GPL (General Public License), ensuring any derivative works remain under the GPL. AGPL (Affero General Public License) addresses server-side applications, the Apache 2.0 License includes a patent license, whereas the MPL (Mozilla Public License) 2.0 balances copyleft and permissive license benefits. Understanding these licenses is essential for both developers and users to ensure compliant and beneficial use of Android's open-source software.

What is the MIT License?

The MIT License is a highly permissive open-source license. It allows users to use, copy, modify, merge, publish, distribute, sublicense, and sell copies of the software with minimal restrictions. The original authors of the software or the source of the software are not liable for any damages that arise from the use of the software. The simplicity and permissiveness of the MIT license make it a popular choice among open source and FOSS developers.

What does GPL-2.0-or-later mean?

The GPL-2.0-or-later license refers to the GNU General Public License version 2.0 or any later version. This license guarantees end users the freedom to run, study, share, and modify the software. If adjustments are made to the software and are publicly redistributed, it must be under the same GPL-2.0-or-later license to ensure all future users also benefit from these freedoms.

What is the GPL-3.0-only License?

The GPL-3.0-only license is the GNU General Public License version 3. This license grants users similar freedoms to the GPL-2.0-or-later license. However, it includes additional terms to ensure these freedoms are retained in more scenarios, including some patent issues. If alterations are made and redistributed publicly, it must be under the same GPL-3.0-only license.

What does GPL-3.0-or-later mean?

The GPL-3.0-or-later license means GNU General Public License version 3 or any future release. Like the GPL-3.0-only license, it grants user freedoms while also addressing some patent issues, but this license also allows for the software to be placed under any new versions of the GPL that may be released in the future.

What is the AGPL-3.0-only License?

The AGPL-3.0-only is a variant of the GPL licenses, known as the GNU Affero General Public License. What sets it apart is that it addresses a loophole where software run as a service over a network could be modified without these changes being shared back to the community. AGPL-3.0-only mandates that even these modifications must be made available to the community.

What is the Apache-2.0 License?

The Apache-2.0 License is a permissive open-source software license that provides rights to users without a significant number of conditions, including the right to use, copy, modify and distribute the software. The license also provides an explicit grant of patent rights and clear provisions on contributions, making it a common choice for large open-source projects.

What is the MPL-2.0 License?

The MPL-2.0 License, or Mozilla Public License version 2.0, is a unique license that combines elements of both copyleft (GPL) and permissive (MIT, Apache) licenses. It allows for the free use, modification, distribution, and private use of the software, but any modifications made to MPL licensed files must be made available under the MPL. This hybrid approach offers a significant degree of openness while benefiting from protections often found in more restrictive licenses.