I’m sure you have your answer already, but let me explain the “running in their own thread” thing :

The callbacks are invoked in the context of the “parser thread” which is the one doing the actual “listening” of the the XML stream. When something happens in the parser thread (e.g. message stanza received), callbacks are invoked from there. So the code you have in your various callbacks are effectively executed in another thread context.

Like Leonardo wrote, you have to write Thread.stop in your main thread when you have set all your callbacks and other initialization stuff.

It might sound confusing, but you have to write Thread.stop to keep the current thread alive. Thread.stop simply put the current thread into sleep mode and leave all the scheduling time to the other threads (the parser thread in our case). If you don’t write Thread.stop, everything ends when the main thread has nothing left to do.

I have updated the original post.

However, there are some little mistakes that i wanted to point out here.
Well I pasted the codes right from the web site and here was the persisting error that kept coming at me when trying to execute the script:

Jabber_test_ruby.rb:81: syntax error, unexpected ‘}’, expecting kEND
Jabber_test_ruby.rb:92: syntax error, unexpected $end, expecting kEND
Tk.mainloop
^
it’s just because you forget to write the “end”s closing block of the callback methods(not all of them).

Anyway keep up the good work, I’ll come back here.