Ruby Cloud Platform as a Service. Enomaly: Elastic / Cloud Computing Platform: Home. Drupal in the cloud. It is not always easy to scale Drupal -- not because Drupal sucks, but simply because scaling the LAMP stack (including Drupal) takes no small amount of skill. You need to buy the right hardware, install load balancers, setup MySQL servers in master-slave mode, setup static file servers, setup web servers, get PHP working with an opcode cacher, tie in a distributed memory object caching system like memcached, integrate with a content delivery network, watch security advisories for every component in your system and configure and tune the hell out of everything.
Either you can do all of the above yourself, or you outsource it to a company that knows how to do this for you.