Rational Developer for System z
PL/I for Windows, Version 8.0, Programming Guide

Why use NMAKE?

The most common use of NMAKE is to automate the process of updating a project after you make a change to a source file. Large projects tend to have many source files. Often, only a few of your source files need to be compiled when you make a change. You set up a special text file, called a description file (or makefile), that tells NMAKE:

This use of NMAKE is only one example of its power. By building suitable description files, you can use NMAKE to:

Rational Developer for System z
PL/I for Windows, Version 8.0, Programming Guide