An Enterprise Service Bus (“ESB”) is a modern integration concept that refers to architectural patterns or specific technologies designed to rapidly interconnect heterogeneous applications across different operating systems, platforms and deployment models.

ESBs include a set of capabilities that speed and standardise a Service-Oriented Architecture (“SOA”), including service creation and mediation, routing, data transformation, and management of messages between endpoints.

With the rise of SOA in the mid-2000’s, ESBs took over from MOM (“Message-Oriented Middleware”) as the leading technology behind EAI (“Enterprise Application Integration”).

Examples of commonly deployed ESBs include MuleSoft’s open source Mule ESB, IBM WebSphere ESB, Red Hat JBoss and Oracle ESB.  The Java Business Integration project (“JBI”) from Apache is also often referred to as an ESB.