What are some alternatives?
Resque - Resque is a Redis-backed Ruby library for creating background jobs, placing them on multiple queues, and processing them later.
RabbitMQ - RabbitMQ is an open source message broker software.
Faktory - a station where factors reside and trade; a building or set of buildings with facilities for manufacturing; the seat of some kind of production… See the full definition
Sidekiq - Sidekiq is a simple, efficient framework for background job processing in Ruby
delayed_job - Database based asynchronous priority queue system -- Extracted from Shopify - collectiveidea/delayed_job
Beanstalkd - Beanstalk is a simple, fast work queue.