Integrated Language Environment

The Integrated Language Environment® (ILE) is the current stage in the evolution of IBM® i program models. Each stage evolved to meet the changing needs of application programmers. For a full description of the concepts and terminology pertaining to ILE, refer to the ILE Concepts book.

The programming environment provided when the IBM i was first introduced is called the Original Program Model (OPM). COBOL, RPG, CL, BASIC and PL/1 all operated in this model. In Version 1 Release 2, the Extended Program Model (EPM) was introduced. EPM was created to support languages like C, Pascal, and FORTRAN. For a full description of the principal characteristics of OPM and EPM, refer to the ILE Concepts book.

The most significant difference between the OPM COBOL/400 environment and the ILE COBOL environment is how a runnable program object is created. The ILE COBOL compiler does not produce a runnable program object. It produces one or more module objects that can be bound together in various combinations to form one or more runnable units known as program objects.

ILE allows you to bind module objects written in different languages. Therefore, it is possible to create runnable program objects that consist of module objects written separately in COBOL, RPG, C, C++ and CL.