Software Engineering: Middleware (Definitions)

"An intermediate layer that may consist of either hardware or software that facilitates interaction across dissimilar hardware and network environments." (Microsoft Corporation, "Microsoft SQL Server 7.0 Data Warehouse Training Kit", 2000)

"A general term for any software that allows two separate and usually already existing programs to exchange data without the need for custom coding." (Richard D Stutzke, "Estimating Software-Intensive Systems: Projects, Products, and Processes", 2005)

"Multipurpose software that lives at a layer between the operating system and application in distributed computing environments." (Judith Hurwitz et al, "Service Oriented Architecture For Dummies" 2nd Ed., 2009)

"Computer software or hardware that connects other software components or systems. This technology evolved to provide for interoperability in support of the move to coherent distributed architectures, which are used most often to support complex distributed applications. It includes Web servers, application servers, and similar tools that support application development and delivery. Middleware is especially integral in managing and optimizing a system-of-systems at the enterprise level. Middleware sits “in the middle” between applications that may be working on different operating systems. It is similar to the middle layer of a three-tier single-system architecture, except that it is stretched across multiple systems or applications. " (David Lyle & John G Schmidt, "Lean Integration", 2010)

"Software that connects software components or applications, functioning as a conversion or translation layer or a consolidator and integrator. Middleware enables one application to communicate with another that runs on a different platform or comes from a different vendor, and it allows multiple processes running on one or more machines to interact across a network." (Janice M Roehl-Anderson, "IT Best Practices for Financial Managers", 2010)

"The term refers to software services that are placed between applications and database servers to make the data interchange transparent and efficient." (Paulraj Ponniah, "Data Warehousing Fundamentals for IT Professionals", 2010)

"Software that allows applications to interact across hardware and network environments." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"software that connects other software." (Bill Holtsnider & Brian D Jaffe, "IT Manager's Handbook" 3rd Ed., 2012)

"Software that connects two otherwise separate applications." (Craig S Mullins, "Database Administration", 2012)

"Software that sits between two or more types of software and translates information between them. Middleware can cover a broad spectrum of software and generally sits between an application and an operating system, a network operating system, or a database management system." (Microsoft, "SQL Server 2012 Glossary", 2012)