I have been dabbling in pure data lately and have grown very fond of the odd noises i can produce.  I am a CS major at the moment so programming is like second nature to me and the idea of programming my own isntruments makes me feel great.  I am just starting, but made a bass drum, snare, and random synth line based on the blues scale.  It was very simple but sounded great to me. 

 I have always had this need to make things from the most simple details up.  It sounds better to me if i thought completely created it.  I always have to use my own sounds when making music and cant deal with preset sounds, and after being introduced to pure data I can see myself having to make everything myself.  It gives me a real sense of accomplishment and feels great.

Who else programs their own isntruments/effects/etc and what got you into it?

What motivates you to continue?