There really are two classes of programmer : the one that build "tools" for other developers, and the ones that build end-user software. Where exactly is the d

There really are two classes of programmer : the one that build "tools" for other developers, and the ones that build end-user software. Where exactly is the distinction? How would you classify Monodevelop, or git/svn, or the C++ STL, or SQLite, or Emacs, or the Unix shell utilities, or Photoshop?