#develop (short for SharpDevelop) is a free IDE for C#, VB.NET and Boo projects on Microsoft's .NET platform. It is open-source, and you can download both sourcecode and executables from this site.

In addition, you can find the latest information and changes on #develop, as well as get in touch with the team in the forum.

Features:
· Forms designer for C# and VB.NET
· Code completion for C# and VB.NET (including Ctrl+Space support)
· XML Editing
· Folding
· Code AutoInsert (Alt+Ins) 
 · C# to VB.NET converter, as well as VB.NET  to C# converter
· Completely written in C#
· Compile C# and VB.NET in the IDE out-of-the-box
· Open source, GPL licensed
· ILAsm and C++ backends
· Integrated NUnit support
· Assembly Analyzer ("FxCop on steroids")
· Xml documentation preview
· User interface translated to many languages
· Everything templated: add new project or file types, or even compilers to SharpDevelop
· Write C#, ASP.NET, ADO.NET, XML, HTML code
· Project or File-based development (Project Scout & File Scout)
· Rich project options
· Syntax highlighting for C#, HTML, ASP, ASP.NET, VBScript, VB.NET, XML
· Intelligent braces
· Bookmark your code
· Code template support
· Feature-rich Find & Replace dialogs
· Easily extensible with external tools
· Easily extensible with Plug-Ins

Download : SharpDevelop 3.0.0.2970 Beta 1 (12.7 MB) | Screenshot | Homepage