Apache License

Apache License

The Apache logo
Author	Apache Software Foundation
Latest version	2.0
Publisher	Apache Software Foundation
Published	January 2004
Debian FSG compatible	Yes
FSF approved	Yes
OSI approved	Yes
GPL compatible	Yes - GPLv3
Copyleft	No
Linking from code with a different licence	Yes
Website	www.apache.org/licenses/

The Apache License (Apache Software License previous to version 2.0) is a free-software license authored by the Apache Software Foundation (ASF). The Apache License (versions 1.0, 1.1, and 2.0) requires preservation of the copyright notice and disclaimer, but it is not a copyleft license — it allows use of the source code for the development of free and open source software as well as proprietary software.

All software produced by the ASF or any of its projects or subjects is licensed according to the terms of the Apache License. Some non-ASF software is licensed using the Apache License as well: as of September 2007, over 2000 non-ASF projects located at SourceForge.net are available under the terms of the Apache License.

Version history

The Apache License 1.0 was the original Apache License which applies only to older versions of Apache packages (such as version 1.2 of the Web server).

The Apache License 1.1 was approved by the ASF in 2000: The primary change from the 1.0 license is in the 'advertising clause' (section 3 of the 1.0 license); derived products are no longer required to include attribution in their advertising materials, but only in their documentation.

The ASF approved an update to the Apache License 2.0 in January 2004. The stated goals of the license included making the license easier for non-ASF projects to use, improving compatibility with GPL-based software, allowing the license to be included by reference instead of listed in every file, clarifying the license on contributions, and requiring a patent license on contributions that necessarily infringe a contributor's own patents.

Licensing conditions

Like any free-software license, the Apache License allows the user of the software the freedom to use the software for any purpose, to distribute it, to modify it, and to distribute modified versions of the software.

The Apache License does not require modified versions of the software to be distributed using the same license nor even that it be distributed as free/open-source software. The Apache license only requires that a notice is kept informing recipients that Apache licensed code has been used. Thus, in contrast to copyleft licenses, recipients of modified versions of Apache licensed code do not necessarily also get the above freedoms.

Two files that must be put at the top directory of redistributed software packages:

• LICENSE - a copy of the license itself.
• NOTICE - A "notice" text document listing the names of licensed libraries used, together with their developers.

In every licensed file, any original copyright or patent notices in redistributed code must be preserved, and in every licensed file changed a notification must be added stating that changes have been made to that file.

GPL compatibility

The Apache Software Foundation and the Free Software Foundation agree that the Apache License 2.0 is a free software licence, compatible with version 3 of the GNU General Public License (GPL).

However, the Free Software foundation considers all versions of the Apache License (as of 2007) to be incompatible with the previous GPL versions 1 and 2. About version 2.0 of the Apache License, the FSF said "The Apache Software License is incompatible with the GPL because it has a specific requirement that is not in the GPL: it has certain patent termination cases that the GPL does not require. (We don't think those patent termination cases are inherently a bad idea, but nonetheless they are incompatible with the GNU GPL.)"

External links

• Apache Licenses