When you consider the cloud, you typically imagine a realm of deployed, production applications. Zend Developer Cloud (ZDC) adds a twist: ZDC creates a place in the cloud where PHP-based applications can be developed for the cloud. No more developing locally, then deploying into the cloud -- ZDC pushes both into the ether.

Independent platform-as-a-service providers acknowledge that theirs is a crowded market, especially with big IT vendors like Oracle, Hewlett-Packard and Dell entering as competitors, but they expressed confidence this week that there is room in the market for many players.

Although code deployment might not be as easy with Engine Yard as with Heroku, the Engine Yard platform is dramatically more tunable. In fact, in many ways, Engine Yard is closer to an infrastructure as a service (IaaS) than a platform as a service (PaaS). Engine Yard provides a base infrastructure tuned to run Ruby applications, but the rest is up to you. Engine Yard does offer Git integration; however, deployment is not executed via a push, as in Heroku, but rather via Engine Yard's suite of tools and its extensive dashboard, which can sync with a Git repository.

In the world of Ruby development, there are two primary cloud-based, platform-as-a-service offerings: Engine Yard and Heroku. Both provide an easy-to-scale, managed hosting environment, both are built on Amazon EC2, and both have a long and intimate history with the Ruby community. Nevertheless, they offer contrasting approaches and features that will appeal to different audiences.

Platform-as-a-service provider Engine Yard is adding support for Node.js as part of a new program at the company designed to help it quickly experiment with new features and services.