Pixelflut: Multiplayer canvas
What happens if you give a bunch of hackers the ability to change pixel colours on a beamer screen? See yourself
Pixelflut uses a very simple (and inefficient) ASCII based network
protocol. You can write a basic client in a single line of shell code if
you want, but you only get to change a single pixel at a time. If you want
to get rectangles, lines, text or images on the screen you have to
implement that functionality yourself. That is part of the game.