I have just finished reading his book Joel on Software and have now been sucked into reading his articles. The book is quite irritating in many places but he's such a good writer with lots of Opinions (yeah yeah) and has occasional insights that it's worth reading. Especially when explaining the world of commercial software development. His thoughts on open source development don't ring so true, mostly I think because he has no deep background in open source work.
A non-organisation I've started makes a terrific product Redland for RDF management and manipulation. It's web friendly, affordable and runs on your server and it's now available for any system with a C compiler. Check it out now -- there's a free online download!