title: How do multiple languages interact in one project?
body: <p>I heard some people program in multiple languages in one project. I can't imagine how the languages interact with each other.  </p>
  
  <p>I mean there is no Java method like</p>
  
  <pre><code>myProgram.callCfunction(parameters);
  </code></pre>
  
  <p>never happens or am I wrong?</p>