Ubuntu to store copies of all users' address books

https://launchpad.net/desktopcouch

"Is there a daemon running by default that brokers communication between
the local applications like evolution and the local couch? Is this
communication driven through D-BUS.. or is there a local unix socket or tcp
port opened as part of the desktop session?"

desktopcouch runs a couchdb for each user session. It's started by D-Bus
activation, so only running if something uses it.

couchdb is a webservice, so communication is then using HTTP.

Thanks,

James