Adapters are small, focused programs that expose functionality and/or data in a legacy application. Our use of this term includes not only the programs, but also the framework for designing and developing adapter programs. Adapters can be deceptively complex, with “thick” adapters performing a variety of functions that include recognizing events, collecting and transforming data, and exchanging data with platform, integration suite or other middleware. However, “thin” adapters may only “wrap” a native application interface, exposing another more-standard one for application access. Adapters can also handle exception conditions and can often dynamically (or with minor reconfiguration) accommodate new revisions of source or target applications.

Adapters are often sold in conjunction with integration middleware products, such as ESBs, integration suites or portal servers, or are offered as a stand-alone product, such as an adapter suite. Among the different adapters, high-level categories include technical and application adapters.

A comprehensive suite should include adapters for:

Common technologies, such as COM, Enterprise JavaBeans and Web services

Industry protocols, such as EDI, Society for Worldwide Interbank Financial Telecommunication and RosettaNet

Common applications, such as SAP or PeopleSoft

Proprietary applications, such as an adapter development kit