Free Form Data Organizer
A "hierarchical spreadsheet" that is a great replacement for spreadsheets, mind mappers, outliners, PIMs, text editors and small databases.
Suitable for any kind of data organization, such as todo lists, calendars, project management, brainstorming, organizing ideas, planning, requirements gathering, presentation of information, etc.
It's like a spreadsheet, immediately familiar, but much more suitable
for complex data because it's hierarchical.
TreeSheets is exceptionally small & fast, so can sit in your system tray at all times: with several documents loaded representing the equivalent of almost 100 pages of text, it uses only 5MB of memory on Windows 7 (!)
TreeSheets is free & open source. Enjoy!
Visit this google group for discussion, and news updates / releases. Grab the source code from GitHub, or file bug reports there / feature requests there. The past donations page. contact the author (Wouter van Oortmerssen) personally.