Middleware is one of those tricky words that more or less describes what it does. It is software that connects different parts of an application or a series of applications. It can be thought of as a sort of glue that holds a network and its connected computers together. Middleware can be a single application, or it can be an entire server.

People can also think of middleware as an adapter device that would run from a new printer to an older computer. The adapter connects the two devices, enabling communication — and, therefore, functionality — between them. Common packages include the Distributed Computing Environment (DCE) and the Common Object Request Broker Architecture (CORBA).

Every type of middleware has the same general purpose: to allow multiple computers to do multiple things across a network or to allow one computer to do many things or one complicated thing across a network. For example, some is used to link a database system to a Web server, allowing users to access the database via a Web browser. Certain complicated computer systems require this type of software in order to run their demanding applications. A perfect example of a large form of middleware is an application server, which is a server that is dedicated to a single application or a single type of application.

Another example would be a suite of software that helps serve an online gaming environment. More and more frequently, online games feature high-definition, high-resolution, graphic-intense presentations. Traditional server solutions are no longer enough to facilitate such online gaming experiences, especially if they are multi-player. Middleware helps bridge the gap, both in reality and in virtual reality.

At its most basic, middleware is invisible, allowing computers to connect and communicate with one another and with servers. Without this software, certain kinds of network activity would be impossible. The more powerful applications become, the more middleware will be needed.

In other Terms…

In the computer industry, middleware is a general term for any programming that serves to "glue together" or mediate between two separate and often already existing programs. A common application of middleware is to allow programs written for access to a particular database to access other databases.

Typically, middleware programs provide messaging services so that different applications can communicate. The systematic tying together of disparate applications, often through the use of middleware, is known as enterprise application integration(EAI).

The term middleware is used to describe separate products that serve as the glue between two applications . It is, therefore, distinct from import and export features that may be built into one of the applications. Middleware is sometimes called plumbing because it connects two sides of an application and passes data between them. Common middleware categories include:

• ESBs
• TP monitors
• DCE environments
• RPC systems
• Object Request Brokers (ORBs)
• Database access systems
• Message Passing