AdaCGI can be used by adding 
  -I/usr/share/ada/adainclude/adacgi -aO/usr/lib/ada/adalib/adacgi
on gnatmake's command line, or by using the project file: see
  /usr/share/doc/adacgi/examples/Makefile
and
  /usr/share/doc/adacgi/examples/examples.gpr