Middleware "dark matter"

Clay Shirky describes PCs as the "dark matter of the Internet" because a lot of them are connected, but they\´re barely detectable. We can apply a similar analogy to middleware because the "mass" of the middleware universe is much greater than the systems - such as message-oriented middleware (MOM), enterprise application integration (EAI), and application servers based on Corba or J2EE - that we usually think of when we speak of middleware. We tend to forget or ignore the vast numbers of systems based on other approaches. We can\´t see them, and we don\´t talk about them, but they\´re out there solving real-world integration problems - and profoundly influencing the middleware space. These systems are the dark matter of the middleware universe.