There will be a lists of open-source VST's, code projects and all kind of music theory resources
Xhip - VST with open source code
Synister - another open-source VST
Randomizer "Fire" http://mdsp.smartelectronix.com/product/fire/ Glitch VST Hysteresis - http://glitchmachines.com/downloads/hysteresis/
KVR Developer Challenge VST's - http://www.kvraudio.com/kvr-developer-challenge/2006/
Many free samples - https://www.freesound.org/home/login/
Sonic Pi pulseaudio problem solving sonic-pi-net/sonic-pi#1109
Akai midimix