FIT  is a testing framework originally created by Ward Cunningham "specifically applicable to acceptance tests like those prescribed by Extreme Programming." Its home site is a Wiki where its ongoing development continues.Dave Thomas re-did FIT for Ruby . Lisa Crispin has promised to test a Tcl version, if one of us will just make the time to create it.In "XP Testing Without XP: Taking Advantage of Agile Testing Practices" , Crispin summarizes that "Fit allows you to define acceptance tests as HTML tables ..."
AM (30 march 2009) Here is A little experiment with table-driven testing, which seems to be at the heart of FIT.
FIT is also a file format written by some gps devices. "The Flexible and Interoperable Data Transfer (FIT) protocol is designed specifically for the storing and sharing of data that originates from sport, fitness and health devices." for more information see http://www.thisisant.com/pages/products/fit-sdk or to decode the files in tcl see reading fit files