TextMate alongside more traditional heavies like OmniOutliner, NetNewsWire, and Delicious Library:

http://maczealots.com/articles/shareware/2005/

TextMate by Macromates is a fabulous text editor for programmers and designers. TextMate offers easy ways to manage your project, keep it organized and automate monotonous tasks. Managing code and markup are made much easier by this application, too. Because most projects require many files, TextMate is also great because it helps you manage all these files. The most commonly used features are the dynamic file outline that allows you to arrange your files in an outline and keep your changes up to date, tabs that make jumping between files simple, a clipboard history so you will never forget where you are going and where you have been and the ability to hide what you don’t use with foldings. TextMate consistently gets high ratings and you can’t beat it for the money.

Some of the MacZealots crew use TextMate to write drafts of stories, create sample code for tutorials and even as a quick outliner. The reason is because TextMate is so lightweight compared to applications like Microsoft Word and Xcode. With less system overhead, we can use our dilapidated iBooks to work on the road.