I've just released Imprimatur-021. The main change is that the <session> element has been removed. There's now just one session for the whole test script. The reason is that I felt that session information didn't fit with the hierarchy of XML. At the moment there isn't a way to start a new session part way through the script. It would probably be done with a 'new-session' attribute of the <request> element. Let me know if that would be useful to you.
With this release I've changed from CVS to Git, simply because Git is more fashionable :-) I used cvs2git and it worked really well.