SciTE - SCIntilla-based Text Editor

SciTE is a free source-code editor for Windows and X. Originally built to demonstrate Scintilla, it has grown to be a generally useful editor with facilities for building and running programs.
On the Download page, you'll find installers and source code, but the one I like is the link to a single-file executable called Sc1. I put Sc1 in an easily-found (short path name) directory on my HDD and on my Cruzer Titanium so I always have a full-featured text editor with me.