Many CIOs wonder what Platform as a Service -- or PaaS -- really all about. Saugatuck CEO William McNee says, "PAAS all the developer tools and services for creating and/or customizing IT and integrating software for folks who want to use hosted computing rather than own it. PaaS might be the whole spectrum of activity that falls between simple turnkey multitenant apps and a pure developer lab for building and bridging something substantial from ground up."
My view is that PAAS is simply meant to be a means to develop, deploy and integrate cloud-based applications, whether public or private. Virtualization was the first cloud platform initiative; just move your apps and databases to virtualized servers. PAAS provides the tools to truly cloud-enable the enterprise. But that requires re-thinking your IT model. As I tried to capture in my book,Zen of Soa
it is this "re-think" that makes cloud such a world-shifting change. No longer tied to your data catner, you can focus on enabling the workforce with a way to collect and combine (in a boundary-free enterprise) an over-arching architecture where business processes are the primary focus, and the business rules that support them.