The AVI Codec Pack is a collection of codecs and filters. Codecs are needed for encoding (and decoding) audio and video. This will allow you to play all major audio and video formats, including DivX, XviD, 3ivx, AC3, and OGG.
During the installation you get to choose which components/codecs to install, and after installation you will be able to play encoded media right away. Version 2.2.1 is a minor release featuring a few bugfixes along with some codec updates.
Requirements: Windows 95/98/Me/NT/2000/XP
Limitations: No limitation