Songbird is an open-source rival to iTunes. It's avaliable for Windows, Linux and Mac OS X.
Previous Windows versions of Songbird were built with code from VLC media player and Firefox.
Today (starting from which version?) Songbird uses gstreamer on Windows (like on Linux)
Songbird was made with code from VLC media player (version 0.8.4a and updates), and today from open-source gstreamer, so should be compatible with most or all of VideoLAN's features.
Do you know more about the compatibility of Songbird? Please add it here