FitNesse was the de facto standard tool for executable specifications and agile acceptance testing but has suffered from several years of relative stagnation. Work is finally underway to revamp and modernise it. The recent release of Slim is the most important upgrade in years and brings FitNesse back to the spotlight. Slim is the new test runner which promises to bring platform interoperability, easier integration, a much simpler programming model and lots of small helpers that will allow us to write and maintain executable specifications and acceptance tests easier. In this session, Gojko Adzic demonstrates Slim and other new FitNesse features and talks about the future of this tool. This is a session for .NET and Java developers. Some prior exposure to FitNesse and FIT would be beneficial, but not required.