Have you recently obtained an MKV file and now you need an MKV codec or specialized MKV player for it? Searching around you might have been confused about the results, since technically an MKV codec does not exist, but that doesn't mean you can't play your MKV file. What you need is an MKV splitter, and there's a good chance you already have proper codecs for your MKV files installed.

Recommended Link: How to play MKV files

MKV (real name Matroska) is a multimedia container; it stores video, audio and subtitle content. Video such as XviD that can be stored in an AVI container, can be stored in MKV too. So for Windows Media Player or something similar to play MKV files, what you need is not an MKV codec but an MKV spliter.

As for an MKV player, there is no main player made exactly for MKV files but there are players with MKV support. Therefore VLC would be considered a good MKV player with cross-platform support on Windows, Linux and MAC, as long as you have the right codecs for the video and audio inside the MKV file (commonly AVC or XviD for video and AC3, DTS or MP3 for audio). Media Player Classic is another possibly good MKV player as it has built in MKV support.