I find IPC::Shareable
I want programs to be able to
exchange some pieces amounts of data;
and I want them to do it quickly. Files are too slow
and "real" TCP/IP networking can be a hastle for just sharing
a little data. Also when the processes aren't related
(i.e. they wouldn't fork to create each other under the
processes model ; they wouldn't be separate threads under
the therading model) it is just really handy to use IPC::Shareable.
Its just that so many people think its either "pipes or TCP/IP"
when their processes need to communicate.
SysV IPC is extremely apropriate for some problems.