Back to the Tolkien computer games pageMUD means Multi User Dungeon. It is a sort of multiplayer text adventure. The players walk around in a usually very large world and can interact with other players in different ways, such as chatting, giving things away, forming parties or simply slaying one another.
Those games that are only partially based on Tolkien's world are italicized.
Some of these may be open for playertesting, but they are not yet finished enough that they have been officially opened.