It's open season on ESBs. Peter Lacey memorably described some of the reports he wrote as an analyst ( “Here’s 30 pages on how you might want to re-architect your software. Here’s 40 pages on why ESBs suck..."). Joe McKendrick wrote an excellent round-up, describing how ESBs are compared variously to Happy Meal freebie toys and house flies.
David Linthicum picks up the riff and describes how ESBs are "on trial". They certainly are, and I would say that the main trial offense is misrepresentation. Too many non-ESB products [app servers, EAI integration hubs] were rebadged as ESBs. This generated skepticism and annoyance.
That is not to say that all ESBs are rebadged. There are notable exceptions. For example, we deployed our XML Gateway recently with the Fiorano ESB, which is a purpose-built ESB (not something else rebadged as an ESB). The TIBCO ActiveMatrix product also looks great (http://www.tibco.com/software/soa/activematrix_service_bus/default.jsp).
It is an interesting fact that people are deploying XML Gateways as a kind of "ESB in a box". It's been known for some time that you can do this with XML Gateways, but I suspect that the poor public reputation of the ESB product category is the reason why this is not shouted about this so much.
Collaboration in 2014
4 hours ago