Another editor, and nothing special. I just thought it finally warranted posting.
I still use SciTE by preference. But on computers where AU3 is not installed (eg. at school) I have a copy of the autoit directory and this on my USB stick.
The screenshot below should show what it looks like.
Features:
Text editor
New,Open,Save
Compile
Run
Error check
Beta/Production Switch
"No save" option - the file is not saved before running/ compiling/ error checking
Version checker (top right)