PPSSPP can run your PSP games on your PC or Android phone in full HD resolution or even higher. It can also upscale textures to make them sharper, and you can enable post-processing shaders to adjust color and brightness the way you like, and other effects.
PPSSPP is an open source project, licensed under the GPL 2.0 (or later). Anyone is welcome to contribute improvements to the code. Thanks to many such contributions, PPSSPP's compatibility is steadily increasing, letting us all play our PSP games on devices of our choice.