作者 Jason 也提到很多人關心的「升級」問題，引述內文敘述：
However, in contrast to Microsoft—which offers a confusing array of full and upgrade versions of Windows, all of them requiring that users enter a unique serial number in order to prove they’re not pirates—Apple continues to rely on the honor system for Mac OS X. Not only does Snow Leopard not require the entry of any serial numbers, but the standard version of Snow Leopard is a bootable “full install” disc that doesn’t actually check for the presence of Leopard in order to install. This also means that if, at a later time, you want to wipe your hard drive and reinstall Snow Leopard, you won’t have to first install Leopard and then run a separate Snow Leopard upgrade on top of it. (That sound you hear is a thousand IT managers sighing with relief.)雪豹將會是完整版的升級片，沒有任何序號、不檢查前套作業系統… All base on honor system!
