Short:  E Preprocessor, "include" source modules.

EPP             E Preprocessor.  Simple, easy-to-use macro preprocessor
                intended for use with Wouter van Oortmerssen's E language
                compiler.  Allows E programmer's to "include" (similar to C)
                E source code modules, thus adding modularity to the E
                language.  Should work on any OS version.  Update to V1.0,
                improved speed; bug fixes; new OPT TURBO directive for turning
                on Turbo mode for single modules; CtrlC made reliable.
                Version 1.1, binary and source.
                Author:  Barry Wills.