VLC Video Player

I am convinced that open-sourced programs are the way to go!  After a few weeks of trying to determine how to play MKV videos on my computer, cousin Eddie informed me about VLC Media Player, an open-source program that is free to download ala Open Office.  Now I have tried playing these high-definition videos with Nero, ffd Show, Win Player and DivX, all to no avail (unless I cough up $5 - $14 for additional audio-video codecs).  With VLC, everything just plays... and plays... and plays...