I just wrote up a new survey article on Ruby and RDF. Some of my conclusions are:
- There's a huge amount of activity surrounding RDF.rb, with over a score of database adapters, serialization/deserialization plugins, and interfaces to other libraries. Most of the recent object mappers have been built on top of RDF.rb, too.
- The popular Redland RDF library has Ruby bindings, and it's actively maintained.
- ActiveRDF was the premiere object mapper for RDF, but it no longer appears to be actively maintained.
- The only recent, active object mapper at the moment appears to be Spira.
- None of the object mappers are taking advantage of ActiveModel yet. This would be really slick, because it would provide much deeper integration between RDF and Rails.
There are also some interesting follow-up comments from the authors of RDF.rb and Spira. Ben Lavender, in particular, has thought a lot about how to sanely map RDF onto Ruby objects.
