Drcd from the ps2dev forums has released a small 2D engine . This is a very cool release. It is special designed for those getting into the PSP development scene or those wanting to learn about developing homebrew for the PSP.
Quoted from the author:
I’ve just released a small 2D engine using pspgl in C++. You can easily draw picture, move them change color, opacity and other things. The only thing that don’t work is the sound. I’ve not found a good enough library to do so. This project was written for Windows Linux (I use OpenAL for sound) and I didn’t find an as good as library. So there is no sound for this moment. But you can make games very easily.