These different targets produced different platforms and price points. For example, Heroku is without a doubt the less expensive option of the two; nevertheless, you're apt to receive far more computing resources for your money with Engine Yard. With Heroku, you receive a virtual slice of computing resources; the sandbox in which your application must reside in a mere subset of what Amazon gives you. With Engine Yard, you get an entire allotment of Amazon computing resources. Engine Yard provides a base platform, and the rest is up to you. Accordingly, Engine Yard stokes the inner sys admin in all of us, while Heroku caters to development skills.
Note that, although both providers reside on Amazon's cloud infrastructure, you only receive one bill. Amazon's charges are incorporated into each provider's costs and passed on to you. In the case of Heroku, the middleman even absorbs the cost for customers who are content to make use of limited resources for free. When you start to use more Heroku resources, Heroku begins to make up for any small losses incurred from its freemium model. The same can be said for Engine Yard. Although Engine Yard gives away 500 hours for a free trial, it makes up any losses eventually when an account begins to pay for resources.
Interestingly, Engine Yard's and Heroku's different market directions seem to have influenced each platform in other ways. For instance, Heroku's documentation is light compared to that of Engine Yard. Whereas Heroku leans on command-line utilities, Engine Yard provides an extensive dashboard. Heroku draws on a much stronger collection of community and third-party extensions than Engine Yard, as found in Heroku's extensive suite of add-ons and rich language support in addition to Ruby.
Regardless of these platforms' initial target markets, both Engine Yard and Heroku now boast a healthy mix of small corporate clients all the way up to large entities. Accordingly, each has a strong community, drawn to the features unique to the respective platform. As Ryan McGeary, the founder of BusyConf and proponent of Heroku, states:
On the other hand, Keith Turner, the head of engineering at Natron Baxter and a strong supporter of Engine Yard, has this to say:
To put it simply, Heroku will appeal more to developers and Engine Yard will appeal to operations folks. Consequently, when evaluating the two platforms, one's choice usually comes down to what's more important: Heroku's rapid deployment via a hands-off infrastructure, or Engine Yard's total control over all aspects of application deployment, provisioning, and monitoring. For the full story, read the individual reviews: