SharpDevelop 1.0 has been released.

http://www.sharpdevelop.com/OpenSource/SD/WhatsNew.aspx
http://www.sharpdevelop.com/OpenSource/SD/Features.aspx

Download:
http://www.sharpdevelop.com/OpenSource/SD/Download/

Features:

• Forms designer for C# and VB.NET
• Code completion for C# and VB.NET (including Ctrl+Space support)
• 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
• ... and much more

Web Development with SharpDevelop, Web Matrix, and DBGCLR

--Mark