Medibuntu – Community Ubuntu Documentation
Non-free restricted contentMedibuntu (Multimedia, Entertainment & Distractions In Ubuntu) is a repository of packages that cannot be included into the Ubuntu distribution for legal reasons (copyright, license, patent, etc).
Some of these packages include the libdvdcss package from VideoLAN and the external binary codecs package (commonly known as w32codecs) used by MPlayer and xine.
RestrictedFormats – Community Ubuntu Documentation
Non-free restricted content
Comments on Linux applications