Like Mac OS X Lion, Mac OS X Mountain Lion will be available via the Mac App Store. However, unlike Lion, the Mac App Store will assess your Mac’s suitability for the Mountain Lion before it lets you download, and pay, for it, according to “512 Pixels” (

Mountain Lion requires OS X 10.6.8 or later, 2GB RAM and 8GB available space on your Mac. The following Macs are supported: iMac (from mid 2007 model); MacBook (from late 2008); MacBook Pro (from late 2007); Xserve (from early 2009); MacBook Air (from late 2008); Mac mini (from early 2009) and Mac Pro (from early 2008).