title: What language is the generated Makefile.in written in?
body: <p>Here is what I think I know (please correct me if I'm wrong):<br>
  configure.ac --- macros<br>
  Makefile.am --- variable definitions<br>
  configure  --- shell script<br>
  Makefile   --- makefile's own syntax   </p>
  
  <p>Despite scanning gnu documentation on automake , I couldn't find out, written in plain words, what language the Makefile.in generated by automake is written in. Kindly help. </p>