title: How can I visualize Fortran (90 or later) source code, e.g. using Graphviz?
body: <p>I've been thrown into a large Fortran project with a large number of source files.</p>
  
  <p>I need to contribute to this project and it would seem prudent that I first understand the source.</p>
  
  <p>As a first step, I'd like to visualize the interdependences between the various source files, i.e. which source files need which modules. As far as I can tell, automated methods exist for other languages and result in a graph that can be built using Graphviz.</p>
  
  <p>But is anyone aware of software out there that can do this for Fortran 90 code?</p>
  
  <p>[Searching the interwebs for Fortran help is a real pain as you end up searching the inter-cobwebs thanks to the painfully ubiquitous FORTRAN 77.]</p>