When Google announced the WebM codec at Google I/O, some in the open source community voiced concern over the license being used. The search giant was using a custom license that had not been approved by the Open Source Initiative (OSI). Now Google has
altered the WebM license
, and is using the well established BSD license.
The original license had some provisions that flew in the face of General Public License. This made it unworkable in the open source community. The rejected version of WebM licensing would have revoked distribution rights for so-called "downstream parties" that file patent suits against Google. In the new GPL-friendly version, companies that file patent suits would have the royalty-free use of WebM revoked, but would still be able to use the codec.
It's not a huge difference in the eyes of many prospective WebM licensees, but it lets the open source community sleep easy. Now WebM just has to become relevant in a web where H.264 already has a big head start.