It was windows developers tools day yesterday, to draw some attention to the free and open source software (FOSS) tools that helps us in doing development.
If i were to pick one single FOSS tool that made quite a difference in my development experience it definitely has to be NUnit. NUnit is the ultimate tool that brought test driven development (TDD) to the .NET world. As most starting out on test driven development, i was also hesitant when i started out test driven development using NUnit. But the more i used it the more addicted i became to this tool. Though now i use VS.NET 2005 for doing TDD most of the times, still there are occasions i jump back to using NUnit because of its simplicity.
So even now for anyone who wants to start out on TDD, just go to www.nunit.org and download the bits and start using it. You will never do programming the same way again.