The project was initially meant to be for a fantasy setting only, but with the acheived stretch goals we have made the engine very flexible. Since Classes, Races, Skills, Traits, Spells, Effects, UI, Rulesets, etc. are all customizeable, authors can create basically any setting they wish. I, for example, recreated the Star Frontiers' module "Crash on Volturnous" for one of the beta builds. Instead of Spells they are called and labeled Powers. I had three classes (Medic, Soldier, Engineer) and a few races (Dralasite, Vrusk, Yazirian and Human).
One of the really powerful features, for those who like this sort of thing, is the scripting language is C# and most everything has been exposed to builders to manipulate/access. For those who don't like to make custom scripts, we have many pre-made scripts that accept parameter inputs so it is as easy as say choosing the gaAddPartyMember script and feeding it the name of the pre-made character file you wish to use for adding the character to the party.
Oh, and I think we have been using IB as the acronym instead of IE as to not confuse it with the Infinity Engine.