Perian QuickTime plug-in updated; A must-have for every Mac

new update includes:

• Added WebM/VP8 support
• Added support for compressed MKV tracks, as generated by newer versions of mkvtoolnix
• Added FFv1 lossless video support
• Added an internal decoder for Theora, fixing compatibility problems with XiphQT
• The readme and license files are now included in the component bundle

Fixes:

• Fixed Matroska files with video glitches due to repeated timecodes
• Fixed several possible crashes in Matroska import
• Fixed some Matroska files losing frames at the end of the file
• Fixed audio sync in many FLV videos
• Fixed several possible crashes/hangs in subtitle parsing.
• Worked around Apple's incorrect channel layout in .mp4 files

recent quicktime post: Lion will introduce new sharing options

source: http://perian.org/#download