Ruins of Cawdor

The Ruins of Cawdor was the last of three graphical MUDs for the online community The Sierra Network, which would later become The ImagiNation Network. It was designed by Richard Aronson (author of the widely reprinted RPG humor story Eric and the Gazebo), and based loosely on Macbeth.
The game was released in 1995, and it was the third one in the series, preceded by The Shadow of Yserbius in 1992 and The Fates of Twinion in 1993. Only The Shadow of Yserbius and The Fates of Twinion were released in offline versions that could be played without an internet connection.
The Ruins of Cawdor has been patched to allow for offline play.