A homebrew library to rule them all...
Create a layer between final code and platform dependant functions. Create a unique library that is capable of do graphics 2D and 3d, manage inputs and outputs, manage audio, and many other things for different platforms out there.
PSP, WII, NDS, WIN32...
Write your code once, and run it over multiple platforms.
Later, scripting(s) interpreter(s) will be added. (Lua, JavaScript)