This post has moved to eklausmeier.goip.de/blog/2013/11-30-working-with-system-v-ipc-queues.
There are a variety of ways to work with queues: You can purchase IBM WebSphere MQ (formerly known as MQSeries), or similar products from Oracle or Microsoft. On most Unix systems queues are already built in, as long as you do not need any functionality to cross machine boundaries, i.e., hop from one computer to the next. If you just need the queuing functionality, i.e., FIFO (first-in-first-out), IPC queues are for you. For example, handling a burst of incoming tasks/orders/messages and one by one working on them individually without the disturbing effect that something else is happening around you.