IDL

The idl file extension is associated with Visual C++.

The idl file contains one or more interface definitions. Each interface definition is composed of an interface header and an interface body. The interface header is demarcated by square brackets. The interface body is contained in curly brackets.

All COM interfaces are defined using the Interface Definition Language (IDL). IDL is similar to C and C++ header files, with new syntax elements specific to distributed computing added. IDL files are compiled to create source files and binary type libraries that can be used by practically all programming environments.

The IDL file extension is also used by CRiSP Harvest. Effects of post-fishery, pre-spawning mortality can be examined through use of *.idl files. Currently, this file only includes estimates of inter-dam loss for Columbia River stocks. Since most inter-dam loss occurs after all fisheries, inter-dam loss is essentially treated as escapement when calculating ocean and terminal area harvest rates. Changes in estimates of inter-dam loss rates can be assessed by modifying this file. It should be noted, however, that the numbers in the *.idl files are actually estimates of total adult survival past all Columbia River dams. Estimated IDL values are used through the present year, then an average of all estimated values is used for future years.

The IDL file extension is also related to CORBA, which is the acronym for Common Object Request Broker Architecture, OMG's open, vendor-independent architecture and infrastructure that computer applications use to work together over networks. Using the standard protocol IIOP, a CORBA-based program from any vendor, on almost any computer, operating system, programming language, and network, can interoperate with a CORBA-based program from the same or another vendor, on almost any other computer, operating system, programming language, and network.