Ok, so we all use NDoc and love it. You do use NDoc, don’t you? Well, you may have stopped using it if you’re doing .NET 2.0 development, because NDoc’s support for .NET 2.0 is, well, not very satisfying. Microsoft has recognized an un-fulfilled need here and started work on a project called SandCastle.
Sandcastle produces accurate, MSDN style, comprehensive documentation by reflecting over the source assemblies and optionally integrating XML Documentation Comments. Sandcastle has the following key features:
Works with or without authored comments
Supports Generics and .NET Framework 2.0
Sandcastle has 2 main components (MrefBuilder and Build Assembler)
MrefBuilder generates reflection xml file for Build Assembler
Build Assembler includes syntax generation, transformation..etc
Sandcastle is used internally to build .Net Framework documentation
You can download SandCastle here.
Dave Hayden has a bit more info about it and some useful tools on his blog.