14.2. Hiding middleware

Middleware is defined as the software layer that lies between an operating system and an application. Middleware is used for interoperability among applications that are running in a coherent distributed system. Examples include Enterprise Application Integration (EAI), enterprise service buses (ESBs), and message queuing software (such as Apache ActiveMQ).

Camel is also used for integrating and providing interoperability among applications that may run in a coherent distributed system. You could potentially view Camel as middleware software, but that isn’t entirely accurate, because Camel leverages third-party software where appropriate. For example, you can have Camel sitting on top of Apache ActiveMQ, and together they’re middleware software.