It’s well-known that XMPP technologies emerged from the open-source server project first released by Jeremie Miller in 1999, as well as the combined software/operator community that grew up around the server.
In the early days, “Jabber” meant many things: Jer’s server, the protocol used between clients and servers, the server network, the community in general, even a company called Jabber.com (then Jabber Inc., purchased by Cisco Systems in late 2008). Over time we have worked to disambiguate the terms. Thus Jer’s server was renamed jabberd and the protocol was renamed XMPP.
However, the relationship between the jabber.org and xmpp.org domains has remained a bit nebulous. Several years ago, the Board of Directors of the XMPP Standards Foundation clarified the matter by stating that the jabber.org domain was a community effort hosted on XSF machines but operationally independent of the XSF. That clarification was never formally announced, but the decision was recently re-affirmed by the current Board so now seems like an appropriate time to make the distinction more public.
The basic division of responsibilities is this: the XSF focuses on the “rough consensus” part of “rough consensus and running code” by defining the core protocols used by the entire XMPP community, as published at the xmpp.org website; by contrast, the Jabber.org team focuses on the “running code” part by offering a popular, XMPP-based, real-time communications service. This focus was incorporated into the recent redesign of the jabber.org website (which now is dedicated to information about the jabber.org IM service), and has long been evident at the xmpp.org website as well.
Now you know!