No, but the WebM license includes a perpetual, royalty-free patent license: http://www.webmproject.org/license/additional/ http://www.webmproject.org/license/a

No, but the WebM license includes a perpetual, royalty-free patent license: http://www.webmproject.org/license/additional/ http://www.webmproject.org/license/additional/ The patent license is irrevocable unless you file a suit against VP8 users claiming that VP8 violates your own patents. (This is a common clause for open-source patent grants; basically it means that Google can still use its patents "defensively" as a deterrent against other patent suits, but it can't use them in an "offensive" first-strike.)