Celery is pretty awesome. Ask has done a fantastic amount of work and invested a lot of time into it. It's pretty quickly turning into the defacto task queue frontend for Django
I played with Celery about a couple of months ago and it was very impressive. It is even more so today. We had problem sets that could have benefited from a job-worker solution, but my current employer is a PHP only shop and introducing this wasn't feasible. We went with a Gearman server backed with MySQL using Drizzle.<p>Either way, Celery is useful and I would like to see how it can handle, if it can, a multi language approach.