When I first started out, I was unaware of other projects being similar, the term used for such software is usually outliners, I've gathered up a collection of other outliners I've stumbled across here, please note that I haven't tested any of these applications, and thus don't really know what to recommend.

OSX outliners
Palm OS outliners:
Linux outliners:
Other outliners
Last modified: Sun Dec 12 17:18:45 2004 (validate) Logo