Beehive has Outlook with OBEO as its most feature rich client.
Clearly, one of the charms of a collab server is its ability to serve a variety of clients, mainly through open protocol support.
Thus, to users of clients like thunderbird and mobile clients focusing on open protocol access, the implementation of the CardDAV protocol could give GAL and address book access to those clients.
There is an enhancement request for that:
ER 9100008: CARDDAV IMPLEMENTATION
The near-to-release version 2.1 of Beehive has this implemented!
If you feel that this enhancement should go as a backport into 2.0.1.x or if you think Oracle should rethink its plans not to release Beehive 2.1 please second this enhancement request through Oracle support.
that would surprise me much, as CardDAV implementation is not mentioned in [Beehive 18.104.22.168.0 Cumulative Patch Set Readme|http://www.oracle.com/technetwork/middleware/beehive/overview/beehive-20170-readme-1666586.html]