I've been evaluating several opensource message queue technologies, such as RabbitMQ, ActiveMQ, OpenAMQ, etc. My question is, what benefits are gained by using a commercial technology such as Tibco EMS, WebSphereMQ, Sonic, etc. instead of something like Active or Rabbit? PHP will be the primary language involved, although Java systems will be interacting as well.
I'd say the benefits are few and far between. You really need to be sure that a commercial system is for you before you invest as there is likely to be no going back.
Some of these things are so esoteric, so prone to vendor lock-in, so damn heavyweight that you'll feel like you have a gorilla on your back, not just a monkey ;)