Engine Yard, the Ruby-on-Rails doyen, is supposed to announce its Engine Yard Cloud platform today along with Flex, a cloud service plan for production-level Rails applications.

The company says its Engine Yard Cloud leverages hundreds of man-years of experience in deploying, managing and scaling some of the world's biggest Rails sites and will put that know-how to work for businesses that want to run Rails on Amazon's EC2 public cloud.

It automates the deployment and management of applications that fetch up to a million unique visitors a month. More and the company will advise shifting to its dedicated infrastructure.

Unlike an infrastructure cloud, Engine Yard provides application-aware auto-scaling, auto-healing and monitoring and a highly optimized, pre-integrated Rails runtime stack.

Engine Yard says the widgetry, which includes redundancy, fault tolerance, load balancing, a MySQL database and a fallback configuration database, is for web teams and developers.

CTO Tom Mornini said, "Given the growing popularity of Rails and the number of developers struggling with infrastructure clouds, the absence of a deployment and management platform for Rails applications was a big gap in the market."

Evans Data estimates that Ruby is used by 20% of the developers in North America and may 3%-5% of developers worldwide.

Engine Yard's Flex plan is for customers that need application-level scaling, reliability and support to deal with traffic spikes in real-time.

Engine Yard Cloud pricing starts at $349 a month for three small instances. Otherwise users can calculate the cost on Engine Yard's on-site price estimator. It comes with 24x7 support.