MSP is Miller S Puckette.
C Sound was the precursor to many of the visual and OO music programming languages, but needed to be compiled and was, well, difficult. Supercollider was heavily influenced by Max/MSP. David Zicarelli of C74 fame had a background in psychology before programming. Kit Clayton wrote the first version of jitter. Autechre are probably the best known artist for using all of the above mentioned software in some form.