Linux (distributions)

Linux is commonly packaged in distributions (also known as "distros"), such as Debian or Red Hat Enterprise Linux, or the simple-by-design Ubuntu (which in turn is based on Debian).

A distribution consists of the Linux kernel and software bundled by the provider (plus various utilities enabling the user to install and maintain those softwares), and is generally maintained by the distributor.

The GNU General Public License (which GNU/Linux is licensed under) allows for the sale of the software (or distribution), provided that the source code to the software is made available (via CD, the Internet, or other media). Distributions that are "for sale" (such as Red Hat Enterprise Linux) are selling the convenience of bundled software, and usually a support contract.