title: System call library
body: <p>How practical would it be to implement a "unified" system call library? Such a library would be a wrapper to the OS's actual system calls. That way, you can write code that makes use of this "unified system call library", and then the library would handle making the equivalent OS-specific calls for you (you'd need to make a different version of the library for each OS). This would allow the easy creation of portable applications.</p>
  
  <p>I suppose this is what wine does, but wine is only for running windows applications on linux. I'm asking about something which allows you to run any compatible application on multiple operating systems.</p>
  
  <p>Has this been done already?</p>
  
  <p>Edit:</p>
  
  <p>Or, better yet, use an existing popular standard (POSIX?) and make wrappers for windows, mac, etc OS calls, so that any POSIX app can run on those respective operating systems.</p>
  
  <p>Double Edit:</p>
  
  <p>After some thought, I realized this is already what a lot of libraries do. But for some reason, there seems to be some calls left out (otherwise why aren't all applications portable across OS's?)</p>