Worlds of Ultima: Martian Dreams was a strange, but novel, game that again featured the versatile isometric engine of Ultima 6 (again with a new graphics tileset). Released in 1991, it is not considered a canon Ultima, not least of all because it apparently happens in a dream.

In Martian Dreams, the Avatar is sent to Mars to rescue a group of famous historical figures who have accidentally been sent to Mars aboard a cannon-launched space-ship.
Nuvie
Produced by: Eric Fry
Website: Nuvie at Sourceforge
Releases:
* Windows Snapshot (all flavours)
* Mac OSX 10.3 Snapshot
* Source

Eric Fry's novel remake of the Ultima 6 engine is also going to be compatible with Savage Empire and Martian Dreams. Though currently being developed under Mac OSX, there are downloadable binaries for both Windows and Mac OSX 10.3 (the developer feels these snapshots might also work under earlier versions of OSX, however this is untested. It is the opinion of Aiera that they will not, simply because of some key API changes that exist between OSX 10.2 and 10.3).

The program source code is also available. Linux users will have to compile Nuvie from source.