PSXSDK 20150729
The PSXSDK is a free and open source software development kit that enables anyone with C programming knowledge to make programs and games for Sony's PlayStation console. Everything was either written from scratch or based on already available open source resources. It is thus free from any proprietary code and fully legal to use. The SDK is mostly geared towards a *nix environment, but is fully usable with emulation environments such as MSYS and Cygwin.