title: What is POSIX compliance and how does it affect me?
body: <p>I keep seeing this come up and every time I look it up I never get a good explanation of what it is or what it means to me.</p>
  
  <p>What is POSIX compliance? How does assuming my program will only be run on POSIX-compliant machines simplify things for me as a programmer? Does it even?</p>