The jabberd project was started by Jeremie Miller, inventor of Jabber technologies, in 1998. The jabberd codebase was the original server implementation of the Jabber protocols (a.k.a. XMPP).
There are, confusingly, two projects named "jabberd":
Despite the numbering scheme, the projects are entirely distinct codebases with different development teams, both projects are actively developed, and neither project should be considered more advanced than the other. For details, visit the project websites linked above.
--stpeter, 2007-03-16