[sketerpot]

A fun thing about the VP8 patent situation: any company which attacks VP8 with a patent lawsuit has their license to use VP8 automatically terminated. From the license:

> If You or your agent or exclusive licensee institute or order or agree to the institution of patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that this implementation of VP8 or any code incorporated within this implementation of VP8 constitutes direct or contributory patent infringement, or inducement of patent infringement, then any rights granted to You under this License for this implementation of VP8 shall terminate as of the date such litigation is filed.

[astrange]

A non-fun thing about that license: it seems to me that it's not compatible with the GPLv2, which doesn't allow adding extra restrictions on the end user. I can't remember if it's compatible with LGPL or not, though GPLv3 seems safe.

This has been raised on ffmpeg-devel, so hopefully Google has some opinion about it.

[jwr]

Actually, this restriction is a subset of the one in GPLv2 and LGPL. And it is very reasonable, as opposed to the GPL ones.

Take a close look at section 7 of the GPL:

7. If, as a consequence of a court judgment or allegation of patent infringement or for any other reason (not limited to patent issues), conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot distribute so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not distribute the Program at all. For example, if a patent license would not permit royalty-free redistribution of the Program by all those who receive copies directly or indirectly through you, then the only way you could satisfy both it and this License would be to refrain entirely from distribution of the Program.

What this means is that if anyone, anywhere, imposes conditions on you (e.g. by way of patent claims), then you cannot distribute the Program at all.

It's a sweeping provision and is the main reason why many companies shy away from the GPL (including some I worked for). It's the reason why we never used XviD, for example — someone, someday, could (and would) come up with patents pertaining to XviD (MPEG-4 ASP) and we would have to stop distributing the software. Meaning, recall the millions of set-top boxes sold.

The restriction in VP8 licensing is much more reasonable — it says that if you come up with patent claims, then you lose the right to do anything with the software.