I'm setting out to learn .NET and get some experience creating a non-trivial project. Microsoft does provide Express (free, Windows-only) editions of the Visual Studio application in a few flavors as well as basic version of IIS with ASP.NET and SQL Server. But, since my current personal development environment is a MacBook Pro (OSX 10.6.7), getting started with development on .NET can actually cost money (mostly due to the Windows tax) . The primary development tool for .NET developers on non-Windows systems seems to be Mono with MonoDevelop . The latest stable release of Mono (2.10.1) supports much of the functionality of the .NET 4.0 platform and some portions of Microsoft's extended .NET eco-system: F#, IronRuby, IronPython, ASP.NET MVC(1, 2, and portions of 3) . The latest beta build of MonoDevelop (2.6 beta 2) provides a lot of support for developing applications using C# and the rest of the CLR. I'll be using these in the coming months to do some experimen