grunwald 

AvalonEdit is the WPF-based text editor used in SharpDevelop. There are two builds of AvalonEdit included in this package. One that targets .NET 4.0 and one that targets .NET 3.5.

NRefactory supports analysis of C# source code: it includes a parser, abstract syntax tree, type system, semantic analysis (resolver), code completion, and several refactorings.

Sample code for AvalonEdit the WPF-based text editor used in SharpDevelop. Modify your App.xaml file so the StartupUri points to the AvalonEdit Sample window: StartupUri="/Samples/AvalonEdit/Window1.xaml"

ICSharpCode.Decompiler is the decompiler engine used in ILSpy.