Middleware

From Wikipedia, the free encyclopedia

To meet Wikipedia's quality standards, this article or section may require cleanup.
Please discuss this issue on the talk page, or replace this tag with a more specific message. Editing help is available.
This article has been tagged since April 2006.

This article is about integration software. For video game engine software, see Game engine#Middleware.

Middleware is computer software that connects software components or applications. It is used most often to support complex, distributed applications. It includes web servers, application servers, content management systems, and similar tools that support application development and delivery. Middleware is especially integral to modern information technology based on XML, SOAP, Web services, and service-oriented architecture.

The term middleware is sometimes considered a buzzword.

1 Definition
2 Origins
3 Organizations
4 Types of middleware
5 See also
6 References
7 External links

[edit] Definition

Middleware is the enabling technology of Enterprise application integration. It describes a piece of software that connects two or more software applications so that they can exchange data.

ObjectWeb defines middleware as: "The software layer that lies between the operating system and the applications on each side of a distributed computing system." <ref>Krakowiak, Sacha. What's middleware?. ObjectWeb.org. Retrieved on 2005-05-06.</ref>

[edit] Origins

Middleware is a relatively new addition to the computing landscape. It gained popularity in the 1980s as a solution to the problem of how to link new applications to older legacy systems, although the term had been in use since 1968.<ref>Gall, Nick (July 30, 2005). Origin of the term middleware.</ref> It also facilitated distributed processing – the connection of multiple applications to create a larger application, usually over a network.

[edit] Organizations

In addition to the existing vendors updating their wares to address the newly expanded vision, vendors such as Mercator, Vitria, Fiorano and webMethods were specifically founded to provide Web-oriented middleware tools. Groups such as the Apache Software Foundation and the ObjectWeb Consortium encourage the development of open source middleware.

[edit] Types of middleware

Hurwitz's classification system that organizes the many types of middleware that are currently available.^{[citation needed]} These classifications are based on scalability and recoverability:

Remote Procedure Call (RPCs) — Client makes calls to procedures running on remote systems. Can be asynchronous or synchronous.
Message Oriented Middleware (MOM) — Messages sent to the client are collected and stored until they are acted upon, while the client continues with other processing.
Object Request Broker (ORB) — This type of middleware makes it possible for applications to send objects and request services in an object-oriented system.
SQL-oriented Data Access — middleware between applications and database servers.

Other sources include these additional classifications:

Transaction processing (TP) monitors — Provides tools and an environment for developing and deploying distributed applications.<ref name="sei">Definition of middleware. Carnegie Mellon: Software Engineering Institute.</ref>
Application servers — software installed on a computer to facilitate the serving (running) of other applications.
Enterprise Service Bus — An abstraction layer on top of an Enterprise Messaging System.