It’s free now, so you don’t need to crack or enter CD-key. Supported macOS versions: 10.6.8 Snow Leopard – 10.14.6 Mojave because no 32-bit apps support in Catalina. Quake 4 for macOS: download the Mac App Store version of Quake 4 from Downloads tab, open *.dmg and copy app to Applications folder. Installing a patch (only for CD version): download Quake 4 1.3 to 1.4.2 upgrade from Downloads tab, install it to the game folder. You can buy digital copy of Quake 4 from Steam or download official CD version from Downloads tab, but for CD you’ll need a valid key.
Install and setup Quake 4 + Q4Max Competition Mod