The Movie Player Very fast movie player with support for almost all known and unknown multimedia formats. Most are supported natively, some with the support of binary codecs. It comes with many built-in audio and video filters that allow completely customizing video and audio. MPlayer also supports a lot of different audio and video output methods. Just to name a few: X11, Xv, SDL, OpenGL and more for video; ALSA, OSS, JACK, ESD,... for audio. For (re)encoding videos there is MPlayer's companion program, MEncoder.
MPlayer is best used from the command line but also includes a GUI (GTK).
Please consider using current SVN version (source only), especially before reporting bugs, since they are often already fixed. Additionally SVN is _very_ rarely broken and usually much better than the last release.
A current SVN snapshot is available here.