Previously asking for KSH 2559 to download, these older versions of macOS are now entirely free. Good news for Hackintosh enthusiasts and retro enthusiasts?
Even though Apple today offers a new version of macOS per year entirely for free, this has not always been the case. In the 2000s and until the early 2010s, Apple asked its users KSH 2559 to switch from one version of OS X (now called macOS) to another.