Just a small note regarding the choice of a 0MQ library and a corresponding perl interface module, as the number of choices may seem overwhelming (three versions of the library, with two different interface modules).
Our site has been running most of the time with a Crossroads I/O library (libxs-1.2.0) with a zmq v2 compatibility layer as offered by this library, and the ZeroMQ 0.21 perl module (from FreeBSD ports). Now we are running with libzmq 2.2.0 (FreeBSD ports) just for kicks, and the same perl interface module - this seems to work fine too. Note that the ZeroMQ perl module can only interface with a version 2 of the library, so native libxs or libzmq 3.* are out). The ZMQ-LibZMQ2-1.01 and ZMQ-LibZMQ3-1.00 perl interface modules seem to work fine too, although I'm a bit concerned with them, considering some compiler warnnings about possible use of undefined values, which seem warranted. Mark
