Although it is payware, I believe
Sublime Text deserves an entry here -- it doesn't expire and is one of the very few programs of its kind entirely cross-platform, as it's available for Windows x32 and x64, as well as MacOS and Linux, allegedly portable in all of them (maybe not so surprising as it's
Python based).
http://www.sublimetext.com/ wrote:
Sublime Text is a sophisticated text editor for code, markup and prose. You'll love the slick user interface, extraordinary features and amazing performance. Some things users love about Sublime Text: distraction free mode, goto anything, multiple selections, command palette, split editing, instant project switch, plugin api, customize anything.
(Animated screenshots viewable at the homepage)

Downloads:
http://www.sublimetext.com/2