Perian is a free, open source QuickTime component (provided as a Preference Pane) that adds native support for many popular video formats, including:
Perian provides a great, free way to convert all of the above formats to other video formats using the QuickTime Player itself, including the iPod video format.
Version 1.2.1 adds/changes the following:
Currently, no user reviews have been submitted. Send me yours!
Can't find what you're looking for? Try a search:
Also, if you have an older Mac, be sure to check out the "Classic" applications page for more options.
Finally, take a look at ALEMIA if you think you know that name of an application, but aren't quite sure.
These are applications that are newer and of potential interest, but which I haven't yet selected for permanent inclusion. Have a look, and let me know if you think they deserve to be part of the permanent collection!