Many things have changed since I started JRDF in 2003. It feels like JRDF has come to a natural conclusion.
Some of them are things I've failed to do very well: get contributors, implement different file format parsers, find enough time to refactor existing bits, etc. I'm also not that interested in Java anymore (as was becoming increasingly obvious as it did have Scala in there at one point and has some Groovy DSL code in there).
The most recent change I've seen is that JSON has achieved some of what RDF was trying to do and I see it more and more in the way people use it to expose their data in a RESTful way. The tooling is less onerous and the ease of use is higher even if what you get is much less.
I've enjoyed developing it and meeting and talking to other people in other groups (especially Jena and Sesame). And of course, none of this would've happened if it wasn't for a lot of other people: Paul Gearon, Simon Raboczi, David Wood, David Makepeace, Tom Adams, Yuan Fang-Li, Robert Turner, Brad Clow, Guido Governatori, Jane Hunter, Imran Khan and Abdul Alabri and the other guys and girls Tucana/Plugged In Software/UQ.