Alex
i think the one with nice JSON output is not optimal, if you need that you should use a browser extension. in firefox for example: http://jsonview.com/
i haven't thought about it yet, but i think LGPL would be best and the only really usable one
it should ask for password automatically. hmmm. logs would be nice. it should ask for password pidgin restart or if you disconnect and reconnect to your xmpp servers
i think i found a possible cause for your problem: you have to enable gpg-agent just add "use-agent" to ~/.gnupg/gpg.conf and it should work
gpg-agent has to be running as daemon. it sets some environment variables, pidgin has to know about. if you type on console: set | grep GPG you should see something...
help on invoking gpg-agent: http://www.gnupg.org/documentation/manuals/gnupg/Invoking-GPG_002dAGENT.html ubuntu does this automatically
you have to have the key of the other persons you want to chat with. there is a feature i implemented to send the public key from within conversation dialog...
i dont have a car...
you could also try https://bitbucket.org/ChernyshovYuriy/openradio/src/master/ it uses the same api