Perian has arrived. The “Swiss Army Knife for Quicktime” indeed, it is the savior to all Mac users who accidentally (or intentionally) try to open those pesky .avi files with Quicktime, but only to find themselves assaulted by a nasty “buy these codecs!” error.
In addition to .avi files, Perian allows you to views the following natively in Quicktime:
As far as we’re concerned, this should be included standard in every installation of Quicktime.
Get Perian now!