Atari MULE Online!

A site by Adam of Evil consacred to play MULE in multiplayer (up to 4 players) through Internet. It offers the AMO Package containing an emulator with network capabilities and an image of MULE. Everything is configured and ready to play. There's an active forum too.

ExtremeMULEing

A site by Ralf Eichberger. Nice Game Tournament Database.

World of M.U.L.E.

A site by Christian Schiller covering lot of aspects of MULE.

Space HoRSE

A windows clone of MULE.

Jack Arrell's M.U.L.E. page.

Ian Muttoo's online manual of MULE

Atari800Win PLus

An Atari 8-bit windows emulator build with a native debugger.

Kroah's Game Reverse Engineering Page of M.U.L.E.

This homepage.