Have you ever wondered why FrontRow does not play your precious AVI/XviD/MKV and the like files? The Answer is the codecs are missing. The missing codecs need to be installed as extensions to Quicktime since FrontRow uses Quicktime to play it’s content listed in the library.
The logical next step is to download the missing libraries and install them one by … really? Actually - no. Luckily there are a few guys that have built a simple solution to install these missing codecs on your mac.
Download the codec pack from perian.org and have fun watching your AVI/XviD/MKV encoded videos.