title: How can I determine the running Mac OS X version programmatically?
body: <p>I have a program which needs to behave slightly differently on Tiger than on Leopard. Does anybody know of a system call which will allow me to accurately determine which version of Mac OS X I am running. I have found a number of macro definitions to determine the OS of the build machine, but nothing really good to determine the OS of the running machine.</p>
  
  <p>Thanks,
  Joe</p>