NDoc

Code documentation is almost always a dreaded task. I am not talking about the early design documents, or even the more detailed design documents; I am talking about documenting individual methods and properties on classes. The NDoc tool will automatically generate documentation for your code using reflection to examine the assembly and using the XML generated from your C# XML comments. XML comments are only available for C#, but there is a Visual Studio .NET Power Toy called VBCommenter which will do something similar for Visual Basic .NET. In addition, the next release of Visual Studio will support XML comments for more languages.

http://ndoc.sourceforge.net.