SynWrite is a free but powerful programmer's editor which comes packed with features and functionality.
A tree structure view for your source makes it easy to locate the code you need, for instance. And with autocompletion, syntax highlighting and code folding you could find SynWrite is more comfortable to use than your regular IDE.
The program doesn't just have to be used for working on source code, though. Features like spell checking, a clipboard history, macros, and an extremely versatile Find and Replace dialog (including support for regular expressions) make SynWrite a capable text editor for many applications.
If there's a problem here it's that SynWrite crams in so many advanced capabilities that it's all too easy to miss most of them. The program supports three types of drag and drop to help reorganise your document, for instance, but that's far from obvious; be sure to browse the menus and documentation to help you fully understand how everything works.
Version 6.38.2720 see full changelog for more):
+ AddonManager uses registry not on SF.net, but on Github - faster
* deleted 4 cmds: "Move cursor N chars up/down/left/right"; use plugin "Move Caret" with same funcs
* deleted 3 opts: "Auto-complete - Auto show words from cur file"; use plugin "Complete From Text" with same funcs
* you should delete old Syn.ini keys: [ACP] File, [ACP] FChars, [ACP] FSize
* change: opt "Keep trailing blanks" changed to reversed opt "Delete trailing blanks"
* change: opt "Auto-show autocomplete after .. chars" moved to Overrides page
- fix: "Auto-show autocomplete after .. chars" didn't work with plugins
- fix: Auto-indent must make line with tab-chars, if tab-chars used