Is Jabber the same thing as XMPP?

I find conflcting information on this subject. Are they the same thing? I've read that Jabber is "based" on XMPP.

For example: The chat client "Pidgin" has a box for XMPP but seemingly not for Jabber. Yet, it seems to support it.

What's the difference between XMPP and Jabber?

From http://wiki.xmpp.org/web/Jabber_Programmer%27s_Guide

The architecture of the Jabber network is similar to email while a Jabber server conforms an email server (server.com) and Jabber clients conforms email clients ([email protected]). The difference is that everything happens (by definition: nearly) in realtime over a persistent XML-TCP stream. In example this makes it possible that other (authorized) users can see your online presence. In addition to that servers can offer specialised services, in example a user directory (users.server.com) or a weather agent (weather.server.com). XMPP is the architecture/protocol the network is based on.

And specifically:

What is the difference between Jabber and XMPP? Since 2004 XMPP is the IETF-approved instant messaging and presence protocol. XMPP is based on the Jabber protocol that evolves since 1998. Basically programming Jabber software today means programming XMPP compliant software.

XMPP is the new name, Jabber the old. So yes, they refer to the same protocol stack.

XMPP is used as name since 2002:

In late 2001 and early 2002, prominent members of the Jabber community decided to once again submit the base Jabber protocols to the IETF, this time as an official submission by the JSF. The first submission was made in February 2002 as an informational Internet-Draft (text | HTML). Following on the success of this submission, it was decided to explore the possibility of forming an IETF Working Group devoted to formalization of the base Jabber protocols, under the neutral name of Extensible Messaging and Presence Protocol (XMPP).

Maybe some background: The name/term 'Jabber' was bought by Cisco and is now a registered trademark of Cisco.