Web Interface Description Language, A Language that defines and standardizes HTTP interactions (requests and responses) between two applications.

Web Integration Definition Language. Developed by webMethods and based on XML, WIDL files are used for automating access to Web resources from within applications. WIDL is particularly well-suited for n-tier Web applications. In many ways, WIDL is similar to CORBA, but is less complex. Its primary functions are location mapping (directory services) and data binding. The WIDL standard has been submitted to the W3C.

a specification that (in this case) describes which portions of data are to extracted and manipulated by the webMethods' Integration Server