Semantic Web Software

As I search for software to empower my thinking (even more than PersonalBrain), I keep coming back to Semantic Web concepts as being closely linked to what I want. I found an exciting gpl project: MindRaider which might become exactly what I'm looking for. In looking deeper, I saw some integration with gnowsis which also may become very useful.

Of course, as I do with new software, I'll wait for a stable release to try them, but I'm very excited about the prospects.