(Well, if this is already possible, I'm gonna look like an idiot, but that's a risk of suggestion...)
Anyways, it'd be cool if it would be possible to look at two different sections of the code, or two different files side by side in the window. Right now, you could only obtain a similar effect by opening the two code files externally and then resizing the windows so that they're roughly next to eachother and then clicking back and forth.
Anyways, I think two frames would be great, for bug finding, and when you need two parts of code that belong in two different sections to work closely together. (Such as a mob and a turf or something like that) Flipping back and forth is annoying.
Anyways, just throwing the idea out there. Sorry if it's an old one or anything.