Last night I was desperately seeking help for some DotNetNuke core classes, and I came up short.  Fortunately I was able to resolve my problem with a little help from Antonio, but I still wished I had a better help file available.

Well, today I discovered that Ernst Peter Tamminga has put together an MSDN-style help system for DotNetNuke.  Exactly what I was looking for.

If you do serious DNN development, this is a must-have.  Thanks Ernst!