Wikipedia
MonoDevelop
MonoDevelop is an open source integrated development environment for Linux, OS X, and Windows. Its primary focus is development of projects that use Mono and .NET frameworks. MonoDevelop integrates features similar to those of NetBeans and Microsoft Visual Studio, such as automatic code completion, source control, a graphical user interface (GUI) and Web designer. MonoDevelop integrates a Gtk# GUI designer called Stetic. It supports Boo, C, C++, C#, CIL, D, F#, Java, Oxygene, Vala, and Visual Basic.NET.