Microsoft has recently released a version of their application that generates the .NET Framework documentation that we see and love...  You can take a look at it and get more information about the project codename Sandcastle here:  Sandcastle Team Blog

Download the December 2006 CTP here:  Sandcastle - December 2006 CTP Download

Some of the high level features:

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

Ed B.