Please note: At this time we do NOT recommend installing Catalina in either beta or final form until our testing is complete. Our latest fully-supported operating system if macOS Mojave (10.14). Sierra was replaced by High Sierra 10.13, Mojave 10.14, and the newest Catalina 10.15. In keeping with Apple's release cycle, macOS 10.12 Sierra will no longer be receiving security updates. MacOS 10.12 Sierra - End of Life Support Ending November 30, 2019Īpple has announced the launch of its new operating system, macOS 10.15 Catalina on October 7, 2019.