Google's updated WebM license
A couple of weeks ago Google announced their WebM project, which provided a free software implementation of their VP8 video codec and a license to exercise the patents the company held on the software. (This after we appealed to them to do just that a couple of months prior.) The license they chose was unambiguously free: a three-clause BSD license combined with a patent license based on one found in the Apache License 2.0. Unfortunately, the interaction between the copyright license and the patent license made the result GPL-incompatible. Based on the concerns of developers writing GPL-covered software, Google publicly stated that they would take some time to review the WebM license and try to address the community's concerns. Today, they released a revised license, and it is GPL-compatible.
The most important part of the change is that Google has separated the patent license from the copyright license. Now the copyright license on the software is a totally standard three-clause BSD license, which is clearly compatible with the GPL. The patent license, in turn, provides distributors with permission to exercise all the rights, and meet all the conditions, in the GPL, as required by GPLv2 section 7; and those permissions are consistent with the ones provided by the patent grant in GPLv3 section 11. All this means that developers distributing GPL-covered software can take advantage of the patent license without running afoul of the GPL's conditions, whether they're using GPLv2 or GPLv3.
We'd like to take this opportunity to thank Google again for helping the free software community out on this issue—both with the initial release of WebM as free software, and by updating the license to address these compatibility concerns. WebM is a great contribution that ensures everyone is free to use the web as it continues to evolve, without surrendering their rights to the patent holders of proprietary codecs. This license update will only make it stronger and even more competitive.