Good tutorials on XMPP?

Question

I've been looking at some open-source XMPP servers, and am familiar with the official page http://xmpp.org/. But thus far I've not found anything in between "The Extensible Messaging and Presence Protocol (XMPP) is an open technology for real-time communication" and a list of XEP specifications. For instance articles explaining the basics and terminology - stanzas, IQ, presence, etc, etc. Even the Wikipedia page misses this, unsurprisingly the open-source projects assume you know these things before you start digging into the code.

Is there a good, (semi-)official set of tutorials on this? Do I need to be looking for Jabber resources rather than XMPP?

Amongst other things, I'd hope to see diagrams for use-cases and flow, not just dry protocol text. I know books on XMPP exist, but generally anything in a book is available in some form online too.

Answer 1

The RFCs (listed on the Wikipedia page) should be a quite good introduction to this topic.

For example: RFC3920: Extensible Messaging and Presence Protocol (XMPP): Core

Answer 2

Here is what got me startet on XMPP Development:

• A good book: XMPP The Definivie Guide
• A mature Java API. I've chosen the Smack Library from Ignite Realtime and used the groovy language with a buch of small scripts to learn the basics.

Later i developed a plugin for the OpenFire XMPP Server. There are some tutorials and a forum on their site as well. I think that both the smack and the openfire api's are easy to learn.

If you are not into java: The book referes to the SkeekXMPP Python library and it uses it to create some examples (echo bot, ...).

Answer 3

As others have said, the specifications are a good introduction. It's true that they are technical in nature, and worded to be precise - but they are really some of the best specifications I've seen for any protocol, especially the new drafts (3920bis and 3921bis) which clarify some of the grey areas in the original RFCs.

E.g. you mention wanting to know the definition of a stanza, it's explained (with examples) in 3920bis section 8.

If you have any feedback on how the specifications can be made clearer, then say so on the XMPP mailing list, where all feedback is considered (though actually 3920bis itself is close to finalization now).

If the specifications are really too much for you (I appreciate some people like more pictures than I do), do consider the book (whether in paper or digital form) - it's designed exactly as an easy introduction to both the core specifications and the most common extensions, and written by people who help develop and implement them.