See http://rdflib.net/2.3.0/ for the 2.3.0 release notes. Briefly,
this is the first release in a new development series of releases --
the API should be compatible with 2.2.x, but be warned that the bits
may still be shifting. The 2.2.x series remains the current stable
series.

Also see http://rdflib.net/contributors/ for the list of contributors.

As part of the 2.3.x work the release process will be expanded to pull
some of this information from rdflib.net when the release is cut -- so
that the information will be included within the release.