I've created a public (read only) repository for ElfBB at svn://svn.graffen.dk/elfbb
Do a checkout of the trunk version, or if you don't want (most probably) broken code, use the unstable branch (svn://svn.graffen.dk/elfbb/branches/unstable) instead.
Various tag-releases are also available, but they're not really all that interesting. Eventually, the repository will be made publicly writeable, for now I'm the only one who can commit. If you feel you wish to contribute, contact me directly by posting on this forum, or at my address at iki(dot).fi, username nikc.