Tetradraw is a fully featured ANSI art editor for Unix operating systems. 
ANSI art is only made up of the ASCII characters with 16 colours. ANSI art is 
mainly used in text mode interfaces. Tetradraw is the first completly usable 
ANSI art editor for Unix operating systems. Tetradraw does not just emulate 
the ANSI editors for DOS: it also allows two artists to edit the same image 
simultaneously over the Internet.

WWW: http://tetradraw.sourceforge.net/