6DX
What is it?
6DX was a product of Eldermage, mainly for an RPG project of theirs, Recluce (not Recluse, as it is often misspelled):
Recluce is an old school CRPG - That is, the emphasis is on story and character interaction rather than on combat like modern "Action-RPGs". Quests are designed to be completed by thinking, though resorting to bashing will work in many cases. Don't get us wrong, we all like a game of shoot-the-wumpus every now and then, but enough is enough.
Recluce was never finished, but Jacob Marner, a student of computer science at the University of Copenhagen, used it for his master thesis, Role Maker, a computer roleplaying game authoring system, in 2001.
Meanwhile, Eldermage is gone and 6DX is free and open source under the MIT license. The last update was 2005-02-15, when Half-Life model support was added to the engine. The project is probably dead.
