[gmack]

Although certainly not without its issues, the most popular solution for that platform is Gearman http://gearman.org . It's fairly ops-intensive, but the most friendly for PHP without having to resort to things like Stomp to interface with messaging (MQ) systems. Which are not optimally designed for job enqueing, per se.

[old_sound]

Why you say that messaging systems are not designed for queueing? You seem to imply that servers like RabbitMQ won't do the job.