Apple has released macOS Sonoma for anyone to download and install on a supported Mac computer. Here's how to do that and why you should upgrade.

Boot into or install Mac OS 9 Alternatively, you can boot into Mac OS 9 if it is installed on the target system, or install Mac OS 9 from included or purchased media, then apply the same firmware ...

One way of avoiding a disastrous upgrade to Apple's latest version of macOS is to partition your Mac's hard drive and install Catalina alongside your current operating system.

Apple today released macOS 12 Monterey, and whenever a new operating system is released for the Mac, some users prefer to perform a clean installation. This article explains how to perform what is ...

Mac OS X Lion is easier to install than any previous version of Mac OS X but things can go awry. Find some solutions here.

Make sure that you are not trying to install the Intel client build on a PowerPC-based Mac, or the Server build on a Mac OS X client system.

Benj Edwards has instructions on installing Debian 4 on a Mac with a 68K processor.