The SciTE Text Editor, whilst being one of the most lightweight editors available, is also one of the best. I created my own package simply to provide a one-stop setup for SciTE with all the extras I, and probably most other people need.
The binaries are straight from the Scintilla website, and I have packed in the context menu fix from André Burgaud and Angelo Mandato.
The installer is built with WiX and of course the sourcecode is available.
The programs menu is created upon install by default.

I have tested this on Windows XP, Vista and Windows 7 32bit & 64bit. The package automatically detects 32bit & 64bit platforms to install and registers the appropriate shell extension from André Burgaud and Angelo Mandato. The shell extension installation is optional as part of the install process.
Enjoy.
SciTE, based on scintilla, is simply the best text and sourcecode editor out there. What makes it the best is its consistent stability, speed (in loading and operation), small size, code/keyword highlighting, bracket matching, folding, tabbed interface, column selection, multiple selection, advanced search/replace, granular customisation and downright simplicity just for editing right out of the box. It is essentially an advanced replacement for notepad - something for coders, scripters, and even the average, non-technical user. It loads up pretty-much as fast as notepad which is a pretty good benchmark. Install it and throw away notepad and every other text editor you might have had the misfortune to install.
SciTE is perfect as a:
You can even customise properties files to handle languages not included with the package. It also works incredibly efficiently on huge files. No more crashes or lockups because the file is too big.
You can visit my review of SciTE with a screenshot here.
Change Log info for SciTE can be found here.