Our company is looking to adopt the TDD methodology. In my opinion, this has more to do with developers than QA folks (feel free to disgree)... regardless, Because of this push JUnit and Nunit are mentioned and so is Fit and FitNesse.

While I'm sure J and Nunit are unit testing tools (name kinda gives it away) what exactly is Fit and Fitnesse? They don't seem to be true automated testing tools but I can't seem to find any info on them. Are they more unit testing tools? what is their relationship to Junit and Nunit and the whole idea behind TDD specifically? Or is there really no relationship?

I have Dl'ed them both and can't seem to run an .exe to see for myself.

What am I missing?