List of features and uses from github:<p>Features<p>Built on Amazon’s reliable and scalable queue service, Connections to SQS are opened lazily negating any initial load time, Multiple queues can be used simultaneously, Doesn’t poll the database, Rails ActiveRecord objects maintain state through the queue, Built-in retry mechanism.<p>Uses<p>FIFO is extracted from the Mine (<a href="http://getmine.com" rel="nofollow">http://getmine.com</a>) codebase. Here are some of the things we use it for:<p>Sending emails, Processing images, Indexing, Sharing to social networks, Cache management, Launching cron jobs, Communication between disjoint parts of a complex application (cron, web, processing servers)