Just what is an ESB, anyway?

Cape Clear recently put out an online quiz portending to expose "counterfeit" ESBs. As might be expected, this marketing piece steered participants toward Cape Clear ESB.

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"It's definitely a clever marketing piece that wants to guide you in the direction that makes the true ESB point in the direction of the [Cape Clear] product," Chappell said.

"They [Cape Clear officials] say they don't require a messaging product. That's a funny way of saying they don't have one," Chappell added.

Cape Clear, with its test, is attempting to clear up the confusion about what exactly is an ESB, O'Toole said. "There are lots of vendors pretending to be something they're not," O'Toole said. He then lists vendors such as IBM, webMethods and, of course, Sonic as pretenders.

"[Sonic] may have invented the term. We're delivering the product," O'Toole said.

Cape Clear's Web services-centric focus is countered by IBM, which does not offer a specific ESB product but says its WebSphere MQ software participates with other products to form an ESB.

"I think there is an ESB in terms of a concept but there are some vendors that are trying to sell an ESB and saying all it needs to do is Web services and I think that is a narrow view of a bus," said Scott Cosby, program director for WebSphere business integration products at IBM.

There are tons of applications that either never will consume a Web service or will not do so for a while, Cosby said. Legacy applications such as CICS and other mainframe systems must be accommodated, he said.

At webMethods, the company believes an ESB is valid for integration scenarios involving basic communications and interoperability between Web services and applications, Clements said. "In more complex integration scenarios [such as integrating with partners], we think companies will look for more than just an ESB," said Clements.

Although Cape Clear said it supports EDI formats via Web services, Clements said ESBs do not actually support EDI. WebMethods provides support for a wide range of integration methods including EDI and RosettaNet.

Pricing on ESB products carry a broad range. Sonic ESB is priced from $30,000 for a single installation of an SOA suite to $200,000 for a moderately sized deployment. Cape Clear ESB has a base price of about $25,000 per CPU, with a typical installation costing $50,000 to $100,000.

ESB user Prast cautioned that deploying an ESB can make your life more difficult in the beginning, because at Rotech it added a higher-level language for declaring variables. It also introduced new structures, procedures and documentation. And the upgrading alone is a time-consuming process. 

"We did it in a test environment first, but it's not a piece of shrink-wrapped software that you just install and you're done with," Prast said.