Compatibility, The DEC Rainbow, and SaaS Multi-tenancy

Fellow Enterprise Irregular Phil Wainright has commented on my recent post regarding multi-tenancy with a well-considered rebuttal that I believe deserves its own rebuttal in turn. Here it is:

As someone old enough to remember the DEC Rainbow and other also-rans, I enjoyed the trip down memory lane. However, at the risk of further disrupting Phil’s dentition, I think he was actually agreeing with me, albeit unintentionally, when he  discussed Wintel compatibility and multi-tenancy in the same light. I think this is the perfect analogy for what I’m trying to say: single tenant vendors can be compatible with the promises of multi-tenancy in terms of updates, pricing, support, etc. even if they stick with their single tenant model, much like any vendor could build to the Wintel spec, and run Windows, without having to duplicate the IBM PC.  Today’s  Mac OS provides a nice example of Wintel compatibility, proving that it’s  unnecessary to buy a Windows machine in order to run Windows. This is the model for my version of the multi-tenancy versus single-tenancy debate:  Like Apple and the Mac’s Windows emulation, I believe single tenancy vendors can simulate the benefits of multi-tenancy without being multi-tenant, and thereby legitimately call themselves SaaS vendors without adhering to SaaS dogma.

Importantly, I think the pricing and services pressure of the multi-tenant vendors will force single-tenant vendors to make their offerings as compatible as possible. But as long as they are compatible with the promises of multi-tenancy, they don’t need to actually be multi-tenant to compete in the market. This is what opened up the PC market to vendors other than IBM, and it is what promises the best possible choices and opportunities for customer. How the vendors arrive at these best possible choices and opportunities shouldn’t matter to the customer, as long as customers get the price and performance they want.