Those examples are then connected to the software with programmer-written test fixtures and automatically checked for correctness.
The customers' examples are formatted in tables and saved as HTML using ordinary business tools such as Microsoft Excel.
When Fit checks the document, it creates a copy and colors the tables green, red, and yellow according to whether the software behaved as expected.
As of June 2005, it has up-to-date versions for Java, C#, Python, Perl, PHP and Smalltalk.
FitNesse is a complete IDE for Fit that uses a Wiki for its front end.