Ubuntu

Ubuntu is an open source operating system based on Linux and intended for "human beings". It is basically installed from a live CD meaning you can test drive without installing, but can be installed from a "Alternate CD", or CLI-based install CD. There are many editions available depending on your preference. Some editions are:
 * Ubuntu (regular, GNOME)
 * Kubuntu (KDE)
 * Xubuntu (Xfce)
 * Gobuntu (GNOME, only free software)

Articles

 * How to install & set up Linux on a Mac by Lucy Hattersley at Macworld (2016-10-06)