Policy on Software which possibly infringe patents
For packages, which include algorithms that are actively enforced by patent holders, we ship them into ubuntu multiverse. Examples for this are MPEG based encoders (like x264, faad, faac, etc).
The rationale for this is that our users expect all packages in ubuntu main and universe to be safe to redistribute and build derivative distributions on. For packages with patented code, this assumtion is not safe anymore. We therefore place these kind of packages into the 'multiverse' section of ubuntu.
For packges, which include a mpeg based decoder are critical. We do ship media players, which are able to play mpeg movies. In order to do that, we need to some packages in main, which includes software implementing mpeg based decoding algorithms. Noteworthy examples for this are 'xine', which requires the packages 'ffmpeg' and 'libmad' to build. However, for legal consideration, we do not want to have mpeg decoder packages on the live cd.
Therefore, packages with only implement mpeg decoding are fine for the 'main' component of ubuntu. However, we implement technical measures to ensure it doesn't get on the CD.
mpeg encoders: => multiverse
mpeg decoders: => main
Technical Measures are to be taken that mpeg decoders are not going on the live CD