The Lessons of Lucasfilm's Habitat

Fascinating to see Mark S.Miller and Drexler cited, as I know a guy who knows them.

On a different topic, Dark Sceptre on the ZX Spectrum was very similiar, but I think the whole multiplayer system (which was done by playing out your moves, inscribing them on a ZX MicroDrive cassette, and posting them to the central control) is probably alive only on some tapes belonging to Mike Singleton.

http://en.wikipedia.org/wiki/Dark_Sceptre