Ability Office 2000 Low cost, full featured (Write, Spreadsheet, Database, Photopaint), very good photo-editor. Evaluation download. Modules available separately. DOS, Windows, Linux port underway.
http://www.ability.com/ More Info
Andrew User Interface System Free, medium featured (word processor; HTML, program and drawing editors; directory and help browsers; spreadsheet; mail/bulletin-board manager; application builder; scripting language), Unix. Open source.
http://www.cs.cmu.edu/~AUIS/ More Info