A single executable program is the typical result, but I dare say it is extensible to a makefile for any purpose at all.
External users can download the source here .
Current public revision is 4.12. A valid sourcefile can also be an includefile. Each sourcefile in the list is presumed to produce an object file with the same basename and a .o extension in the current working directory. If more than one sourcefile in the list would produce identically-named object files, only the first is used and the rest are discarded. Please note that precedence descends from left to right.