| Since ESB was first introduced in 2002, the ESB approach to integration has been adopted by numerous significant vendors in the middleware, integration, and web-services markets. Its acceptance continues to grow steadily. Analyst firms such as Gartner Inc., IDC, and ZapThink have been tracking and writing about the ESB technology trend since early 2002. In a report issued in 2002 (DF-18-7304), Gartner Inc. analyst Roy Schulte wrote the following: A new form of enterprise service bus (ESB) infrastructure combining message-oriented middleware, web services, transformation and routing intelligence will be running in the majority of enterprises by 2005. These high-function, low-cost ESBs are well suited to be the backbone for service-oriented architectures and the enterprise nervous system. Those four pillars MOM, web services, transformation, and routing intelligence represent the foundation of any good ESB. This book will focus on the role of each piece and many other required components as we explore the ESB. We will examine what the ESB can do for an enterprise, and the role that each basic component plays. We will also explore some advanced topics, including architectural overviews of practical uses across a number of industries. 1.6.1 Vendors Adopting the ESB A number of middleware and integration vendors have either built, or are in the process of building, something that matches the description of the ESB. And the list is growing all the time. The Appendix lists all the known vendors. Some vendors say they are providing an ESB already; some have announced plans to create one; some are just using the terminology in marketing materials but don't really have anything substantial behind it. This technology category is destined to become as hot as application servers were in the late '90s, when more than 25 vendors were competing for the same technology space. A few vendors in this list deserve special mention. Sonic Software pioneered the concept, and shortly thereafter a number of other smaller vendors got on board, saying they also were providing an ESB or were in the process of building one. Once the incumbent integration companies such as webMethods, SeeBeyond, and IBM finally got "on the Bus" and announced their intent to build an ESB, the ESB term really began to get widespread notice as a growing technology category with staying power. At the time of this writing, Microsoft has not publicly made any statements regarding its Indigo project and the term ESB. However, some journalists and analysts made that connection when Indigo was first announced. A November 30, 2003 ComputerWorld article, "Developer interest piqued by Microsoft technologies," quoted Roy Schulte of Gartner Inc. regarding Indigo: Roy Schulte, an analyst at Gartner Inc. in Stamford, Conn., noted that Indigo is a superset of Microsoft's Messaging Queuing (MS MQ) technology, as well as the company's Component Object Model (COM), COM+, .Net remoting and Web services support. "Think of this as a simplification, a unification of communication middleware on behalf of Microsoft's plan," he said, adding that he sees Indigo as a very good enterprise service bus (ESB). Indigo is based on messaging and has the notion of combining MSMQ and web services. That could provide the basis for a messaging bus. However, the rest of its integration capabilities are locked into BizTalk, which is a hub-and-spoke integration server. To qualify as an ESB, both a distributed message bus and distributed integration capabilities need to exist. If nothing else, the completion of Indigo will make applications and services built on the Microsoft platform even more attractive as endpoints to connect into an ESB. The inclusion of Indigo into the Microsoft platform and development environment will facilitate making applications capable of being loosely coupled and messaging-aware. | 