I'm just getting starting into C for FRC, and I know a few others such as:
Lua - A game generic language, I mainly code it for Garrys Mod
C++ - Know very little, couldn't code it for my life
Visual Basic - For school only, I would really rather NOT know this
Dark Basic - Another school language. It's a pretty cool program, Dark Basic. It's a 3D game creator with about Nintendo 64 rank graphics.
Then there are the standard ones that most people know:
HTML
Javascript
Flash Action script