The Darkflame was an experimental sim - there was no set crew, captain, or background. A mailing list of interested simmers was maintained, and any were free to attend as they wished. Missions would be organized spontaneously, with a different crew member serving as captain each time. The missions always centered around a Federation starship called the USS Darkflame, although the class, era, and other information associated with the ship would change from mission to mission.
The Darkflame was launched in the autumn of 1998 by Chas Hammer and M. L. Moses. The idea of a free form sim proved successful, and was soon adopted by the two in Trek Online as the basis for the New Horizons sim. In the summer of 1999, Chas and Moses attempted to launch further sims modeled off of the Darkflame and establish a full fledged club, (alternatively called "Trek Theater" or "Outer Realm Sims"), but time constraints forced them to abandon the venture. Ultimately, many members of the Darkflame ended up joining New Horizons or a separate sim established after the Darkflame folded, the USS Erasmus.