Heh, I'm going overtime with the #OldComputerChallenge, but #NetBSD is SO FUN to use on the Pi1!
I'm now running JWM, the dillo browser, Pidgin and PCManFM in addition to my busy multiple pane tmux session, and yet the RAM does not go over 260MB! It's amazing, this is like hooking up a motorcycle to pull a wagon of load, adding more and more weight and that motorcycle never slows down despite the load!
Props and props to the devs, this is definitely my new favorite OS for the raspberry pi!