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GitHub User: robertmay
@Marquisdebad It really depends on what you want from a queue system. I personally use beanstalkd to process incoming email on an app. It's not supposed to be as powerful as the other options you suggest; it's a simple and very fast queue system.
A couple of corrections for you:
* it does have persistence; launch the daemon with -b
* it may not have the size of userbase as DJ, but it does have some very high traffic users. I believe http://ravelry.com does for a start (and obviously Causes on Facebook, for which it was created).
I love it because it's incredibly simple :)