The “cloud” terminology has been around for a while, but it was broadly popularized when Amazon Web Services started offering its S3 storage service and its EC2 compute service. With these services, you could easily store data or run software without owning or managing the physical infrastructure. Quickly, Software-as-a-Service (SaaS) companies like Salesforce.com realized that there were similarities between their offerings (which had been around for almost a decade) and this new “cloud.” So as not to be left out of the hype cycle, they started calling their offerings “cloud.” Fair enough: indeed, with SaaS you don’t have to manage the infrastructure or the software.
Lately, though, it seems that partisans of this model − I am talking specifically about SaaS that is shared-everything, and multi-tenant at the application and database level − are attempting to abscond entirely with the term. I’ve had industry analysts and others tell me that, for all intents and purposes, Cloud means multi-tenant SaaS. When I challenge this point of view by asking whether Amazon EC2 is “cloud,” they mutter something about it being transitional, or mainly for online games, or for high-performance computing. Certainly it’s not where enterprises or ISVs should be, according to this viewpoint.