OCP (OPES Callout Protocol)
The OPES WG (Open Pluggable Edge Services Working Group) of IETF was formerly charted in February 2002 and concluded in March 2007.
The OPES mailing list is still alive. A description of the work group, the list of reached milestones and RFCs can be found
Part of the work was a new callout protocol (working title OCP for OPES Callout Protocol) with an
application agnostic core (RFC 4037) and profiles per application protocol it should handle
(for example the HTTP profile defined in RFC 4236).
Technically OCP has some advantages over ICAP/1.0 and has been proposed as ICAP/2.0 but at this time,
OCP has not been implemented in any commercial shipping product.