When I installed dmake 4.13.1 into prefix /opt/local...

./configure --prefix=/opt/local
make
sudo make install

...it installed these files:

/opt/local/bin/dmake
/opt/local/share/startup/config.mk
/opt/local/share/startup/startup.mk
/opt/local/share/startup/unix/macosx/macros.mk
/opt/local/share/startup/unix/macros.mk
/opt/local/share/startup/unix/recipes.mk

It doesn't seem right for dmake to claim ownership of the "startup" subdirectory of DATAROOTDIR; someone seeing this directory later might wonder where it came from, and this directory name could conceivably conflict with one installed by other programs. The possibility of such confusion and conflict would be eliminated if the files that are installed into DATAROOTDIR were installed into a subdirectory named after the program (e.g. /opt/local/share/dmake/startup).