Development Environment for GNOME

 MonoDevelop is a GNOME IDE primarily designed for C# and other CLI (.NET)
 languages. It is the unbranded version of Xamarin Studio.
 .
 It supports the following languages: C, C++, C# (1.0, 2.0 and 3.0), Vala, Boo,
 Java, Nemerle, ILasm, ASP.NET and VB.NET.
 .
 Features: Debugger Integration (Mono Debugger and GNU Debugger),
 Class Browser, Assembly Browser, Built-in Help, Monodoc Integration,
 Code Completion (also known as IntelliSense), Code Folding, Color Schemes,
 Code Refactoring, On-the-fly error underlining, XML Editing, Embedded HTML
 viewer, Gettext support, GTK# Designer, MSBuild project support and
 Makefile Generation.