The Cupertino-based company made the move when v10.9 Mavericks was released. Those who want to buy the OS can do so at the Mac App Store for $19.99. Those who want it for free can get the download codes on the official support webpage.
Mac OS X Mountain Lion requires a Mac Pro (early 2008 minimum), Mac mini (early 2009 minimum), MacBook Air (2008 minimum), MacBook Pro (2007 minimum), MacBook (2008 minimum) or iMac (2007 to 2020), while the Mac OS X Lion requires a Mac that has a pre-Mountain Lion OS.
Users will need at least 2GB of memory, 8GB of available storage space and a processor of at least Intel Core 2 Duo or Xeon processor. The full list of requirements are available to view on Apple’s official download page.