Who doesn't like a good ESB? Cask-conditioned, served at cellar temperature with a nice foamy head. But that's enough about my preferred ESB—namely, the classic English pub ale known as Extra Special Bitter.

Of course, in the technology and SOA (service-oriented architecture) world, ESB means something completely different: Enterprise Service Bus. And this particular combination of three letters has caused even more confusion than its sibling acronym, SOA.

Pretty much every vendor involved with integration, Web services and development has tried to position itself as having an ESB solution. ("See, you just take our database, plus this IDE, add some messaging stuff, tweak this sample code, and tie it together with duct tape and Elmer's glue and, voilà, an ESB!")

But this is one area in which I have to agree with analyst companies and say that an ESB is an actual product, not a strategy. Tying the definition of an ESB down to a tidy little sentence or two is still a daunting task (it would have something to do with seamless, directionless services communication), but it's one of those instances where you'll know one when you see one.

I've been looking at ESBs for a forthcoming review feature, and I've seen some nice streamlining in the commercial offerings, with more centralized development and management capabilities. And open source is starting to make itself at home in the ESB market, with a couple of promising options recently arriving on the scene. Look for my evaluation in the Aug. 7 issue and at eweek.com.

This article was originally published on eWEEK.com.