There are plenty, but few/none that solve the problem Disque solves. You could easily use Kafka or RabbitMQ, but Disque aims to provide simplicity rather than be full-featured. @antirez described it as solving the case where you just need a queue with very basic guarantees and good performance without all the bells and whistles that a more complex system has. Disque is (spiritually, not technically) a lot like Mongo was five years ago compared to something much heavier like Postgres. In that sense, there are few (if any) product-ready alternatives that solve the same problem.

It should also be noted that you could probably successfully use Redis for much of what Disque does (Disque is based on Redis). Disque adds nice features, though, and removes most of the features of Redis that are outside its scope.