In August 2004, I wrote that the "bus does not stop here." I explained that enterprise service buses, the 21st century form of message oriented middleware (MOM), were becoming popular underlying middle-of-the-stack software. But they were not being used very often free standing, that is, just to replace enterprise application integration (EAI) software for example. More interesting, many users were starting to build a service-oriented architecture (SOA) without an enterprise service bus (ESB). It wasn't logical but the marketplace rarely is.
The next time I looked, about 18 months ago, that pattern still held. I did find that the number of "bus routes" had grown however. By that I meant that suppliers that had originally offered ESBs only underlying their other midstack software had begun to offer ESBs a la carte as well. IBM and BEA were leading examples of that trend. Still the suppliers' preference was to sell you their 'higher order' software, enabled by the ESB, rather than just sell you the ESB. "The bus still did not stop" with just the bus, and therefore the ESB market as a separate entity was not booming. IBM and BEA telegraphed their new ESB plans for a year before they announced, which probably held ESB adoption back. (Fear, uncertainly and doubt works throughout the information technology [IT] market and is not just an anti-open-source-software (OSS) phenomenon.)
