Linux
A family of software operating systems (OSes). Many different variants of Linux exist, created and maintained by different groups. Linux is known for being open-source, meaning any programmer can obtain the source code and create their own tweaked version.
See: OS
Linux has been most popular as an OS for servers, although versions also exist for desktop computers and mobile devices.
There are several variants of Linux for mobile devices, including Google's Android.
See: Android
