macOS Catalina (macOS 10.15) is here for the Mac; if you are not already aware, this macOS will kill any 32-bits apps you may have installed on your computer. Apple has been working with developers over the past few years to transition from 32-bit to 64-bit hardware and software technology for the Mac.
macOS Mojave was released Monday, Sept 24th and it is amazing. I have been waiting for a very long time for a "dark mode" because I must admit, my eyes need relief since I spend many hours a day on the computer working and gaming.