SharpDevelop

SharpDevelop is an integrated development environment for .NET development. As a free and open-source alternative to Microsoft Visual Studio, SharpDevelop features project templates, refactoring, code completion, and debugging tools for stepping and breakpoints. You can also use SharpDevelop to convert code between C#, VB.NET, and Boo. SharpDevelop provides native compatibility with Visual Studio project files and is extensible with plugins to give you all the tools necessary for development in the .NET Framework.