title: Does the Mac Developer Program have old versions of Mac OS X?
body: <p>I'm developing something for Mac OS X. It's a port of a Windows product.</p>
  
  <p>One of my boss' concerns is how it will run on older versions of Mac OS X. I know Xcode has <a href="https://stackoverflow.com/questions/2857295/compiling-for-older-versions-of-mac-os-x">facilities</a> for compiling for old versions of Mac OS X, but QA would prefer to actually run the older versions of Mac OS X on a Macintosh. </p>
  
  <p>Since we got into Macintosh development after Snow Leopard was released, all of our machines come with Snow Leopard (10.6). As far as I know, you can't really walk into a store to buy Leopard (10.5) and anything prior to that is basically extinct.</p>
  
  <p>In a <a href="https://stackoverflow.com/questions/3018097/how-is-clean-testing-done-on-the-macintosh-without-virtualization">question on virtualization</a> someone said that they've done multi-boot or multiple hard drives for other versions of Mac OS X, but I'm not sure how one would obtain the install media or the license for an old version.</p>
  
  <p>I see Apple has their <a href="http://developer.apple.com/programs/mac/" rel="nofollow noreferrer">Mac Developer Program</a> which touts as one of its features as "access pre-release versions of the latest software" which is cool, but I don't see it anywhere on there that old versions of Mac OS X are available. Does Apple have an MSDN-equivalent where old versions of the software are available for download? </p>
  
  <p>Also, is there a reliable breakdown somewhere of the rate of upgrades/updates to Mac OS X? (i.e., what % of users still run Mac OS X 10.5, 10.4, PPC-based machines, etc.)</p>