code: def compatible_platforms(provided, required):
      
      if provided is None or required is None or provided == required:
          # easy case
          return True
  
      # Mac OS X special cases
      reqMac = macosVersionString.match(required)
      if reqMac:
          provMac = macosVersionString.match(provided)
  
          # is this a Mac package?
          if not provMac:
              # this is backwards compatibility for packages built before
              # setuptools 0.6. All packages built after this point will
              # use the new macosx designation.
              provDarwin = darwinVersionString.match(provided)
              if provDarwin:
                  dversion = int(provDarwin.group(1))
                  macosversion = "%s.%s" % (reqMac.group(1), reqMac.group(2))
                  if dversion == 7 and macosversion >= "10.3" or \
                          dversion == 8 and macosversion >= "10.4":
                      return True
              # egg isn't macosx or legacy darwin
              return False
  
          # are they the same major version and machine type?
          if provMac.group(1) != reqMac.group(1) or \
                  provMac.group(3) != reqMac.group(3):
              return False
  
          # is the required OS major update >= the provided one?
          if int(provMac.group(2)) > int(reqMac.group(2)):
              return False
  
          return True
  
      # XXX Linux and other platforms' special cases should go here
      return False
docs: Can code for the `provided` platform run on the `required` platform?
  
      Returns true if either platform is ``None``, or the platforms are equal.
  
      XXX Needs compatibility checks for Linux and other unixy OSes.