I've built a release candidate of xerces-c-3.1.3 for testing. This is a bug fix release to address some reported issues and I am targeting late February for the PMC to approve the release.
I noted there's a dev/ tree in the dist.apache.org svn repository, though I haven't located a URL that maps to it apart from svn directly. You can find the unofficial RC1 source distributions here: https://dist.apache.org/repos/dist/dev/xerces/c/3/sources/ -- Scott