It's like a cellular automata sound-programming language.
Each key stands for some musical object -- "p" might generate pitch values, "m" might send a MIDI signal somewhere, "g" ("g"enerate?) might send letters across the screen that do something when they hit another thing, etc. You "write music" by putting a bunch of letters on the screen and then watching how they interact.
I've seen it mentioned a few times online but never wrote it down.
[I'm not thinking of taking up another language -- I need that like I need bacon pants. But a friend of mine is into cellular automata and I think he'll dig it.]