MPlayer

You can watch VideoCD, SVCD, DVD, 3ivx, RealMedia, Sorenson, Theora, and MPEG-4 (DivX) movies too. Another big feature of MPlayer is the wide range of supported output drivers. It works with X11, Xv, DGA, OpenGL, SVGAlib, fbdev, AAlib, libcaca, DirectFB, but you can use GGI and SDL (and this way all their drivers) and some lowlevel card-specific drivers (for Matrox, 3Dfx and Radeon, Mach64, Permedia3) too! Most of them support software or hardware scaling, so you can enjoy movies in fullscreen. MPlayer supports displaying through some hardware MPEG decoder boards, such as the DVB and DXR3/Hollywood+. And what about the nice big antialiased shaded subtitles (14 supported types) with European/ISO 8859-1,2 (Hungarian, English, Czech, etc), Cyrillic, Korean fonts, and the onscreen display (OSD)?

The player is rock solid playing damaged MPEG files (useful for some VCDs), and it plays bad AVI files which are unplayable with the famous windows media player. Even AVI files without index chunk are playable, and you can temporarily rebuild their indexes with the -idx option, or permanently with MEncoder, thus enabling seeking! As you see, stability and quality are the most important things, but the speed is also amazing. There is also a powerful filter system for video and audio manipulation.