POSIX message queues allow local processes to exchange data in the form
of messages.  This API is distinct from that provided by System V
message queues, but provides similar functionality.

* http://bogomips.org/ruby_posix_mq/
* ruby.posix.mq / librelist.com
* git://git.bogomips.org/ruby_posix_mq.git

Changes:

This supports Rubinius 1.2 as well as Ruby 1.9.  Ruby 1.8 works except
it will block the entire interpreter for blocking operations.  Spurious
errors during GC for POSIX_MQ#to_io users are now avoided.

-- 
Eric Wong