htpc-menu is a frontend to mplayer for use on linux or Mac OS X. It is written in C and uses libsdl, libsdl-image, and libsdl-ttf. This program will only be a basic file browser that launches mplayer.
You are better off using mplayer's OSD menu and getting some of the scripts for GEEXBOX 1.*. I am working on this and you will find my resulting work on the Puppy (GNU/)linux forums