I have been having problems playing mkv video file format on my Mac. The Divx player kept complaining about missing Dolby AC3 decoder. After doing some googling, it turned out the VLC Media Player is the choice.
You can download it from Mac Update
VLC Media Player Description:
VLC Media Player is a highly portable multimedia player for various audio and video formats (MPEG-1, MPEG-2, MPEG-4, DivX, mp3, ogg, …) as well as DVDs, VCDs, and various streaming protocols. It can also be used as a server to stream in unicast or multicast in IPv4 or IPv6 on a high-bandwidth network.
- Free to use
- Plays almost anything
- Great hotkey support
- Basic interface limited by few skins