SharpDevelop is a free and open source integrated development environment for the .NET Framework, Mono, Gtk# and Glade# platforms. It supports development in C#, Visual Basic .NET, Boo, F#, IronPython and IronRuby programming languages.
SharpDevelop was designed as a free and lightweight alternative to Microsoft Visual Studio, and contains an equivalent feature for almost every essential Visual Studio Express feature and features very similar to those found in Borland Kylix and Delphi, including advanced project management, code editing, application compiling and debugging functionality.