SubEthaEdit

From Applepedia

SubEthaEdit
Min/Max OS Support	10.2 / 10.3
License	Shareware
Category	Internet
Installer	No
PowerPC Traitor	{{{universal}}}
Website	SubEthaEdit

SubEthaEdit is a nice text editor that is free for non-commercial use. You can edit documents with other people editing them at the same time and see their cursor and typing. Magical!