1. Amazon Simple Queue Service is a fully managed message queuing service.

  2. RabbitMQ is an open source message broker software.

  3. Resque is a Redis-backed Ruby library for creating background jobs, placing them on multiple queues, and processing them later.

  4. Apache Kafka is an open-source message broker project developed by the Apache Software Foundation written in Scala.

  5. Google Cloud Messaging is a service that enables developers to send data from servers to both Android applications or Chrome apps.

  6. Iron.io is the leader in cloud application services. IronMQ is a highly available message queue solution and IronWorker is a powerful async task processing service.

  7. Sidekiq is a simple, efficient framework for background job processing in Ruby

  8. CloudAMQP automates every part of setup, running and scaling of RabbitMQ clusters. Available on all major cloud and application platforms.

  9. ZeroMQ is a high-performance asynchronous messaging library.

  10. Gearman provides a generic application framework to farm out work to other machines or processes that are better suited to do the work.