As Ms Talon has said, AlliED is only current mission editor out there (that's updated that is). Also, there are no 'new' ones either.
However, there are a few other editors, albeit a little
There is the New Horizons editor, which I personally didn't like too much. Psykhed was actually becoming a pretty good editor, possessing no map, but having quite more options available than New Horizons, short one briefing editor. Psykhed also had support for unknowns, such as dynamic mission goals, and proximity triggers, which I figured out.
The first was a poorly made editor, and I think there was only one version of it anyway. Mission Architect was it's name, and to this day, I believe it is still the only editor available at The Outbound Flight Filezone. hehe
Go for AlliED, it has solved unknowns, a very nice briefing editor, accurate map, wireframe models for that precise positioning, and is just plain fun
Troy is also looking into loading opt wireframes, so custom ships will show up properly on the map, as well as a few other things. Since there might be some OGL involved it might take some work, but it would definitely help out those people who have custom ships installed.
Official Staff-Lacky at XWing: Legacy
"Man who stands on toilet, is high on pot"
[This message has been edited by Sheldon (edited May 19, 2000).]