Celery: Distributed Task Queue is described as 'Celery is an asynchronous task queue/job queue based on distributed message passing. It is focused on real-time operation, but supports scheduling as well' and is an app. There are more than 10 alternatives to Celery: Distributed Task Queue for a variety of platforms, including Windows, Linux, Self-Hosted, Mac and Ruby on Rails apps. The best Celery: Distributed Task Queue alternative is RabbitMQ, which is both free and Open Source. Other great apps like Celery: Distributed Task Queue are Apache Pulsar, Zenaton, ØMQ and sidekiq.