The $29 retail Snow Leopard upgrade disc--as well as the $10 upgrade disc available to people who purchased a Mac on or after June 8, 2009--is for users who already have a license for Leopard (OS X 10.5). Apple says those with Intel Macs running Tiger (OS X 10.4) must buy the $169 Mac Box Set, which includes a full version of Snow Leopard bundled with the latest versions of iLife and iWork.
However, the Snow Leopard upgrade DVD does not require that you have Leopard installed; it's a full install disc that works on any Intel Mac. Similarly, as with every version of Mac OS X, Snow Leopard does not require activation or a registration code; Apple continues to rely on the honor system. This is great for Leopard users, as it makes it much easier to install Snow Leopard on your Mac without having to jump through hoops; for example, if you decide to erase your hard drive before installing Snow Leopard, you don't have to first install Leopard.
合法性 tiger 要買 OSX + iLife + iWork 軟體套裝
Leopard 可買 $29 美元 "升級版" 剛出貨的電腦可買 $10 美元 "升級版"
但是實際上 Snow Leopard DVD "升級版" 並不需要 檢查 Leopard 再硬碟中 即可安裝