You linked to the Theora page, not the Vorbis page.<p>Also, just because Xiph <i>says</i> there are no other patents doesn't mean there <i>are</i> none.  It takes an incredible amount of IP research in order to be confident of such a claim.  Probably only Sun has done enough to make this sort of conclusion--they did an incredible amount of IP research for the development of Sun OMS.  The spec, though terrible, is worth a read just for its coverage of IP-related issues.<p>This is primarily a problem for corporate adoption: companies are scared <i>shitless</i> of submarine patents.  Many would rather have the devil they know than the devil they don't.  It's the same problem with promoting corporate use of open source software: many companies would rather have a proprietary license that makes them feel secure than even a BSD license that guarantees nothing.<p>Even if Theora and Vorbis are both actually patent-free, the mere fear that they aren't is enough to scare many companies off.