Vendors offering ESB technology can be broadly separated into three camps: pure-play ESB companies, application server vendors whose products can be customized to meet ESB requirements, and traditional EAI players that are building support for Web services standards on top of their integration platforms.
Forrester Research analyst Mike Gilpin describes pure-play ESB products from companies such as Sonic Software, Fiorano Software Inc. and Cape Clear Software Inc. as "lightweight ESBs" that generally can be used off the shelf at a fraction of the price of EAI offerings.
Lightweight is not a pejorative term, says Gilpin. "What we really mean is that it is easy to implement and maintain, as opposed to light in not having good capabilities," he says.