The Apache-2.0 license was drafted on the "license" mailing list at apache.org, which has since been closed, but archives of the license mailing list are available. The draft license was updated on December 24, 2003, and January 20, 2004, to reflect the first two rounds of comments by the public. The final 2.0 license was approved by the ASF board on January 21.

The license helps us achieve our goal of providing reliable and long-lived software products through collaborative open source software development. In all cases, contributors retain full rights to use their original contributions for any other purpose outside of Apache while providing the ASF and its projects the right to distribute and build upon their work within Apache.

Licensing of Distributions¶

For more than two years, we have worked on improvements to the Apache License in order to solve several deficiencies with the old one. We had the following goals in mind (not in order of preference):

1. Clear
   Lots of questions get asked about 'can I include Tomcat/Jserv/xxx in my commercial product,' even though careful reading of the current license answers that. It may be better to be verbose if that cuts down on frequently asked questions. Likewise, many lawyers have commented that the original license did not define the terminology precisely. Solved in 2.0 by defining most important terms and separating the permissions into identifiable sections.

2. Reusable
   The Apache- and ASF project-specific stuff should be separated out of the license proper so that both ASF and non-ASF projects can use the license terms unaltered. Currently, each ASF project has its own, altered, version of the main ASF 1.1 license template. Solved in 2.0 by moving project-specific stuff into the NOTICE file.

3. Trademarks
   Avoid listing a specific set of trade marks, trade names, and service marks within the license, since that caused problems with project-specific licenses and apparent GPL-compatibility. Likewise, provide instruction on how and when Apache marks may or may not be used, since that is our most common source of licensing question. Partly solved in 2.0 by excluding any permission to use trademarks within the license itself and moving related information into the NOTICE file.

4. Compatible with other licenses
   Since the ASF aims to create software that implements reference standards, it's in the interests of the ASF and ASF software users to aim for "compatibility" with other widely used software licenses, where "compatibility" means that our software can be used and redistributed as part of a combined work. Special preference should be given to other widely-used open source licenses, to help avoid reinvention of the wheel. Partly solved in 2.0 by modifying trademark clause and moving attribution notices into the NOTICE file.

5. Patent protection.
   It would be nice to have some language in the license that protected us and our users from patent-infringement suits, at the very least from contributors if not in more general ways. Solved in 2.0.

6. Covers contributions
   How do we ensure that contributions are made under our license and not under some other conditions? Solved in 2.0.

7. Applicable to documentation
   Make the license clearly applicable to both software and documentation. Solved in 2.0.

8. Includable by reference
   We should be able to replace all the copies of the license in our files with pointers to a license file and/or a URL. And the license should state that this can be done, and define the conditions. Solved in 2.0.

9. Short!
   Complete license should be as short as possible, and with as little opaque legalese as possible. Less than a page is excellent; shorter still is even better. This is the trade-off -- we lost shortness in exchange for more clarity and extra patent and contribution coverage. However, the 2.0 license is still considerably shorter than comparative licenses, and the ability to license by reference makes the actual citations within source files much shorter than before.

Apache License, version 2.0¶

http://www.apache.org/licenses/LICENSE-2.0

A big thank you goes out to all those who commented on the proposals. The Apache License, version 2.0, was approved for use by Apache projects as of January 21, 2004, with all Apache projects required to move to the new license by March 1, 2004.

Contribution Agreements¶

Updated contribution agreements were also published and the latest versions are available at ASF Contributor Agreements.