PyXMPP is a Python XMPP (RFC 3920,3921) and Jabber
implementation. It is based on libxml2 -- fast and
fully-featured XML parser.

PyXMPP provides most core features of the XMPP protocol and
several JSF-defined extensions. PyXMPP provides building
blocks for creating Jabber clients and components. Developer
uses them to setup XMPP streams, handle incoming events and
create outgoing stanzas (XMPP "packets").

WWW: http://pyxmpp.jabberstudio.org/