We've had nothing but problems with ActiveMQ and we've been using it for 4-5 year now. We've been slow on making the decision to move to a different open source implementation because it is difficult to test this kind of software. I mean, ActiveMQ appears to work fine in tests, but in production, lock-ups and storage leaks happen on monthy basis. We need simple functionality, peristent queues in their simplest form. HornetQ seems like a good candidate. I'd appreciate if anyone could share their experience with it.