Zileas: We plan on releasing our full set of game tools, which is one program: StrifeEdit. StrifeEdit has everything I as the designer have used, as well as everything the art team uses to insert art, everything the music/sound team uses to put in music and sound, etc. It also has a level editor, which is what you would expect it to be.
There are several things that separate StrifeEdit from comparable programs. The first is that we are releasing it, so it's "official" and supports all it can. If you look at Starcraft, which has a HUGE demand for such a tool compared to most games, it took years for people to get out a complete toolset by reverse engineering the data file formats. We'll give players that functionality up front.
The second is that StrifeEdit is not a scripting language compiler or anything like that. It's actually a program designed to be used by people who aren't particularly proficient with computers. A few things certainly are more technical than others, but a lot of games can only be modified by really ugly modification of scripting code, especially for the more advanced things. StrifeEdit is instead completely graphical. There are a few screenshots of it on our website to show examples, but I guess results speak louder. So to provide an example, last night I implemented the Tainted Wisp, which is an unannounced Accursed unit as of this interview. It took me about 3 or 4 minutes to slap in the frames our lead artist (Joe Poppa) provided, then another minute or two to configure the fact that they are somewhat transparent. Then, I had the ability to summon it as a spell and nearly all of its abilities (a few aren't coded yet) integrated into the game within another 10 minutes. So that's a total of 15 or so minutes for one unit, which really isn't bad. Naturally the big difficulty is getting good art to go in the game, but I don't think anyone's going to make an automated tool to do that quickly any time soon.
StrifeEd lets you create new tile sets, units, races, buildings, animations, interfaces (you can completely redo much of it save a few basic rules), weapons, modifiers (things that alter how a unit works), spells and more. Pretty much anything can be done with it, save a few special tasks that have to be hard coded (like some really strange spell effect, although the library we will have just from fulfilling our needs will be pretty good). Adding sounds to units or replacing them is very easy too.
We also have file synching code that allows you to easily get stuff from people you try to play against. For instance, let's say you make The Simpsons total conversion, and I want to play against you. All I have to do is join your game, and the program will ask if I want to download your configuration files for it and it'll download the files right then on the fly, like other RTSes download maps)