This player will probably become one of the best, for the moment it already supports MPEG-4, DivX, MP4, AVCHD and HDV, up to 64 different video and audio tracks and two screens. Furthermore, it includes the possibility to add plug-ins. Since it's open source, the possibility of external contributions is very high, and the amount of plug-ins and add-ons for VLMC will surely increase as time goes by.
The software has a rather rough interface, but it's more than enough to start using it. Even if it isn't a professional tool, it is more than enough for domestic or semi-professional environments, so if you need an editor with quite a lot of possibilities, VLMC is an option worth taking into account