Sandcastle Help File Builder
The Sandcastle Help File Builder was created to fill in the gaps, provide the missing NDoc-like features that are used most often, and provide standalone GUI and command line based tools to build a help file in an automated fashion. A Visual Studio integration package is also available for it so that help projects can be created and managed entirely from within Visual Studio.
Sandcastle doesn’t churn out the sexiest documentation by anyone’s standards, but it’s automated and dead simple to set up.