Since releasing my latest book, Enterprise Service Bus (O'Reilly Media, 2004), I have been doing a fair amount of visiting corporations, conducting seminars, and generally discussing with enterprise architects the subject of enterprise service-oriented architecture (SOA) and how an enterprise service bus (ESB) backbone can be leveraged to provide a framework for an enterprise SOA. Along the way, I have been asked many questions about the nature of an ESB. I have also fended off some misconceptions that have been growing in the general IT population regarding what an ESB is and when, where, and how it can be used. I have gathered together the most popular questions and misconceptions, and offer some clarity in the form of a "top ten" list.