Many “El Capitan ISO” downloads on forums, torrents, or file-sharing sites contain malware, modified kernels, or adware bundles. If a site asks you to disable SIP or install a profile — run.
Some of the notable features of El Capitan include:
sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/ElCap --nointeraction
as the system-wide typeface, a font specifically designed for legibility on Retina displays. 3. Key Features and User Experience