How about document pane of opened files?
After trying many text editors / IDE's on the Mac, I must say I find CotEditor the best! I use it on a daily base for my frontend and PHP development.
One thing that I bump into everytime is the tabs for the opened documents. While it's an OK solution for having a few files opened, it gets fuzzy when say 5 or more files opened, as you can imagine. Reading the filenames horizontally is a pain for the eyes and very time consuming:

May I mention one program which did a perfect job back in the day? Textpad: solved it as simple as this (no complicated nodes are folders that can be folded / unfolded) -- it worked like charm:

Hopefully I'm not the only one thinking this is a time saver! Thanks and keep up the good work. Jeroen.
If no folder/project view is coming, please add at least this feature.
The open document list is in Window menu, I think it shouldn't be too hard to make it to a pane.