One of the complaints analysts often make about vendors is that they offer their own definitions of SOA – often conveniently tailored to match their needs -- and thus add to the confusion over what is and is not SOA.

Someone even came up with a name for it, Vendor Driven Architecture – and it's intensely frowned upon.

Of course, that doesn't keep vendors from doing it.

IBM recently decided to expand its own definition of SOA, according to Mike Vizard, a veteran IT journalist who oversees our new CTO Edge site.

What changed? Vizard says IBM now defines a SOA end point as anything that can be construed as a service, which, he notes, means even a simple Javascript application would now be considered SOA-enabled. He continues:

“Instead of thinking about integrating code, customers are going to look to integrated business processes that will be enabled by multiple levels of SOA capability. Ideally, each end point would be as mature as possible in terms of SOA capabilities, but IBM is committed to be substantially less puritanical about what characterizes a SOA-enabled end point.”

The post goes on to note that IBM foresees companies using multiple ESBs based on application requirements, rather than maintaining a single ESB standard. This, of course, will require a federated approach to managing these ESBs.

Vizard also notes that it will require a more robust set of middleware:

“In IBM’s expanded definition of SOA, the intelligence that governs the interactions between all the services is being handled centrally by a more intelligent set of middleware technologies. This governance process, which in the context of IBM is established through a Websphere Service Registry Repository (WSRR),  is going to be especially important because the growth of SOA going forward is going to be a lot more organic.”

Now, far be it from me to decide whether IBM's revised concept of SOA is right or wrong, or even whether it furthers the field of SOA or IBM's own marketing agenda. I'm sure people who are paid much more than me will have something to say about it.

But I would like to point out that there's been some speculation that as SOA's hype cycle flattens out, SOA spending may follow suit. And IBM, as Vizard notes, attributes 57 percent of its software revenue to middleware sales.

I also think it's worth pointing out that IBM recently announced a slew of  updates to its Websphere products, including the edition of Websphere Message Broker version 7 and WebSphere Enterprise Service Bus version 7, which provide new "service federation management."

But even if analysts believe IBM and other vendors shouldn't redefine SOA, it's hard to place all the blame for SOA confusion on vendors. After all, it's not as if SOA's definition is written in stone ... or even paper. Recently, I interviewed analyst and architect JP Morgenthal about how his definition of SOA has evolved to include seeing SOA as a strategy, rather than an architecture. Inevitably, a reader posted an attempt to clarify “what people think they mean when they use the term 'SOA.'”