The system is based on rooms which can contain objects and where people can meet in real time.
Communication is generally by means of typing a command word followed by a sentence in English.
In general peoples' activity is restricted to the current room. A MOO is a MUD built on Object-Oriented principles. MUDs and MOOs have great potential for educational purposes and professional communication . There is also a quick reference card . The time and date in the Birkbeck Crystallography MUD is in Greenwich Mean Time .