Apache Software License
Definition - What does Apache Software License mean?
The Apache Software License (ASL) is a license scheme for free and open-source computer software (FOSS) written by the Apache Software Foundation (ASF). ASL allows projects and software to be freely downloaded and used, may it be in whole or in part, for personal, company or commercial purposes and without concern for royalties. The code is distributed openly and is allowed to be freely modified, redistributed or studied. Through open-source code, Apache encourages users to voluntarily improve the design of the software.
Techopedia explains Apache Software License
The Apache Software License is an indicator that the software is free, however Apache still requires the distributed Apache software to have a copy of its license included clearly and easy to find; as well as a clear attribution to the ASF for any distributions that include any Apache software.
Modified code or software is no longer regarded as Apache’s, and would be attributed to the developer who modified it, even though it still retains ASL. Modified software is forbidden to be used in any commercial property or trademarks that may use or imply that the ASF endorses the distribution. It also forbids the use of any trademarks or logos owned by the ASF that may suggest that the individual that modified the code created the Apache software in question. Essentially, any piece of Apache-originated software should be redistributed with proper attribution.
Users are not required to send their code changes back to the ASF, however feedback is encouraged. It is also not required to include the Apache software itself or modification that has been done in the code to be distributed. Apache License 2.0 is GPL compatible as long as the software is licensed under GPL version 3.0.