I'm looking for a good, preferably free, test planning and documentation tool. Ideally something that will keep track of which tests have been run against which software version, with reporting ability. There's a whole bunch of tools listed here but are there any others, and which ones have you had the best experience with? (You do run tests, right?)
UPDATE 2008-01-29
So far TestLink and Fitness have been mentioned. A related question yielded also a link to the ReadySet project, an open collection of software planning documentation templates.
I have used TestLink and found it okayish, but I cannot say I enjoyed using it. Has anyone had any experience with Fitnesse? Or are there any other free tools out there that you have used and found satisfactory?