Ok, bascially if you put the developer.exe, they are the same as the game, but when you working on a mod and you change the entity files, instead of having to restart the game, it will dynamically reload the entity files with the new data in it, of course, it will be reloaded if all you have changed is the values not whole lines (not unless you rebuild the entity you have just altered), and it will also tll you if you have an error in the code
ok say you have ship 1 with ability 1, now if you changed the ships values such as numbers, it will automactically load in the new numbers
but if you have ship 1 with ability 1 and you replaced it with ability 2, the ship that is already built will have ability 1, but if you build a new one, it will have ability 2
things such as meshes, and abilities will require a new ship to get it replaced. but numbers it will automcaically do it
of course it has other features, but it is best if you just open up the program and look thru it yourself, words can't really begin to describe it.