We have our subscribers in our website in the Joomla RSMembership module. We want to synchronize the membership with our mailing list in MailChimp. So if somebody subscribes on our website, he would be added to our MailChimp list, into the proper group (based on his subscription type), with a subscription date. If somebody unsubscribes, or their subscription expires, they would also be added to the "subscription expired" group in MailChimp.
This should be set up as an RSMembership module that could be added via Joomla's interface.
MailChimp PHP API: [url removed, login to view]
MailChimp API documentation: [url removed, login to view]
Joomla RSMembership documentation: [url removed, login to view]