MPlayerOSX is binary distribution of MPlayer (The Movie Player for Linux) and comes with native GUI in Mac OS X. After installation you can simply (by Drag&Drop) play almost all 3ivx, DivX 3,4,5 and other codecs files in the window or fullscreen mode.
Rendering of very nice antialiased text-based subtitles is also supported.
MPlayerOSX is a multimedia player with playlist, supporting playback of all widely used media types (MPEG 1-4, DivX, AVI, ASF, Ogg Vorbis, RealMedia, QuickTime Movie, MPEG layer 1-3, AC3, WindowsMediaAudio etc.) and movie subtitles of various formats (MicroDVD Player, Subrip, etc.).
MPlayer has an updated, very efficient postprocessing. For every image from the movie, Mplayer applies a filter to reduce square areas.