The Free On-line Dictionary of Computing (30 December 2018):

imake

   A tool which generates Makefiles from a template, a set of
   cpp macros, and a per-directory input file called an
   Imakefile.  This allows machine dependencies (such has
   compiler options, alternate command names, and special make
   rules) to be kept separate from the descriptions of the
   various items to be built.

   imake is distributed with, and used extensively by, the X
   Window System.

   (1995-02-21)