It's been written about before, but it bears repeating: it seems that suddenly every computing product calls itself a platform. In the early days of computing we made programs (when was the last time you met someone that called themselves a programmer?), then at some point that didn't sound good enough, so they became systems, but that started to imply green-screen terminals, so the new object oriented kidz started calling stuff frameworks. More recently, the SOA crowd got us calling stuff services. Now platform has become the term du jour, with everyone from chip makers to graphics designers jumping on the bandwagon.

That's the way it goes, I suppose. It's really hard to summarize in a sound-byte definition, but I'll make a stab:

Platform-as-a-Service (PaaS) is an offering that provides solution developers the necessary services to implement solid applications, where the application execution environment, development and testing tools, administration and configuration, and runtime monitoring are provisioned in the cloud.

Here are some corollaries to that definition:

A PaaS should:

• enable rapid time-to-market for solutions
• massively scale
• provide high availability and fault tolerance
• provide a standard security model
• abstract the physical infrastructure completely from the application
• provide standard services that are tailored to the general domain (i.e. a PaaS for remote asset intelligence should provide strong support for Assets and Communications as first-class concepts)
• provide an integrated model for the application lifecycle: develop, test, deploy, maintain, end-of-life
• have a comprehensive and open API that is consumable by the widest possible set of technologies

That's a really, really high bar. To me, calling something a platform implies an absolute commitment to addressing the above list. That's what it takes to walk the walk.