Perian, The Swiss Army Knife of Quicktime Components (just look at the logo) has release version 1.1. The popular QuickTime component allows you to play most popular video formats in the QuickTime player and FrontRow. Specifically Perian adds support for: AVI, FLV, MKV, MS-MPEG4 v1 & v2, DivX, 3ivX, H.264, FLV1, FSV1, VP6, H263I, VP3, HuffYUV, FFVHuff, MPEG1 & MPEG2 Video, Fraps, Windows Media Audio v1 & v2, Flash ADPCM, Xiph Vorbis (in Matroska), and MPEG Layer II Audio.

Additional improvements include:

• Major performance improvements
  
• TrueAudio, MP1, and DTS audio support
  
• Slice-based multithreaded decoding for MPEG-1/2/H.264
  
• Apple H.264 now handles AVCHD/interlaced video
  
• Compatibility fixes for QuickTime 7.4 and Leopard
  
• Objective-C GC compatibility
  
• Fixed a crash in Toast
  
• Better subtitle rendering
  
• Subtitles play during MKV loading
  
• Snow support
  
• Miscellaneous bug fixes

Version 1.1 requirements: Mac OS X 10.4.7, and you may download it for free from their website.