Middleware serves to simplify the communication between processes. It is an abstraction layer between the lower network layers and higher-level processes or applications. Its aim is to disguise the complexity of applications from each other and configure the exchange of information (data) as easy and transparent as possible. More on this can also be found at Wikipedia/Middleware.
Without doubt, OPC (OLE for process control) and CORBA (common object request broker architecture) are among the most important middleware solutions in the field of embedded and in automation technology.
Middleware is often said to be too big and too cumbersome, and only applicable to large machines. And especially not relevant for tasks that depend on short response times.
Modern developments such as OPC UA or Corba ACE/TAO demonstrate the opposite day after day. Here at Linutronix, we have expertise in both approaches and will gladly support you with the implementation of these technologies.