TSO/E REXX defines a format for compiled REXX execs so that TSO/E REXX can distinguish between compiled and interpreted execs. TSO/E REXX also provides a defined interface for an installation to install a REXX compiler runtime processor.

Compiled execs are executed by a compiler runtime processor. To initiate run-time processing of a compiled REXX exec, TSO/E uses a compiler programming table to identify the run-time processor and up to four interface routines. You can modify the compiler programming table to identify routines for a compiler runtime processor, if a compiler runtime processor is installed. Each of the four compiler interface routines are optional and, if installed, can provide special processing for the initialization and termination of the compiler runtime processor, loading of compiled REXX execs, and accessing REXX variables.