I started work on an editor for RiL, and it's going relatively well, been having some fun with RegEx. I'm starting to get the hang of it; I've dabbled with it before, but I've never done anything with Negative lookbehind, Negative lookahead, etc.
So far I've got a nice tab system going as well as some basic syntax highlighting(keywords, single line comments, strings). I've still got loads of work to do though, gotta do some .NET Reflection for the auto-complete. I also need a project manager, which will have a tree-view to the left. It's getting there, but I'd say I'm ~30% done.
Here's a screenie.
Believe it or not, depending on the file size, it takes the editor a while to parse each file for highlighting. After the file is loaded it does the highlighting per line after the user types. I think I'm gonna end up threading the highlighter, so the user doesn't have to wait when they open a script for editing.