The creation of the ESB has been an evolutionary process. As we just discussed, a number of events in the industry had their part in catalyzing the creation of the ESB (Figure 3-1). This does not mean to imply that the predecessors of ESB were bad or failed technologies. Each contributing technology in the ESB ancestry was the best available for its time and continues to have its "meritt"[sic]. The ESB draws positive influences from its predecessor approaches, and avoids the downsides.
Figure 3-1. ESB catalysts: a timeline of technology and other events affecting the creation of the ESB
The invention of the ESB was not an accident. The ESB is a result of vendors working with forward-thinking customers who were trying to build a standards-based integration network using a foundation of SOA, messaging, and XML. These customers came from the end-user IT community in the manufacturing business, and from e-Marketplace infrastructure and trading exchange companies such as CommerceOne and GE Global Exchange Services (GE GXS).