On2 represents and warrants that it shall not assert any rights relating to infringement of On2's registered patents, nor initiate any litigation asserting such rights, against any person who, or entity which utilizes the On2 VP3 Codec Software, including any use, distribution, and sale of said Software; which make changes, modifications, and improvements in said Software; and to use, distribute, and sell said changes as well as applications for other fields of use.
Xiph.org development projects are available to the public through read-only Subversion (SVN) access.
Access to Xiph.org can be handled basically two ways:
Once you've installed the Subversion client, just type
svn co http://svn.xiph.org/trunk/theora
to check out the Theora codebase.
Once you've got the repository checked out, you no longer need to specify this full path; the repository location is stored with the checkout. svn update will sync your local copy with the repository. See the SVN manual for additional information on how to use SVN.
Subversion uses HTTP (and WebDAV) as the protocol, so you can just use a normal web browser to browse around the repository. This can be useful for looking at a few files, if you don't want to check out the entire module.
To do this, just point your web browser at http://svn.xiph.org/trunk/theora
The source for the legacy VP3 codec for Quicktime and Video for Windows can be obtained by changing the theora module name in the lines above to vp32, as in svn co http://svn.xiph.org/trunk/vp32.