Linux for mobile devices, sometimes referred to as mobile Linux, is the usage of Linux-based operating systems on portable devices, whose primary or only Human interface device (HID) is a touchscreen. It mainly comprises smartphones and tablet computers, but also some mobile phones, personal digital assistants (PDAs) portable media players that come with a touchscreen separately.
Mobile Linux is a relatively recent addition to the Linux range of use, with Google's Android operating system pioneering the concept. While UBPorts tried to follow suit with Ubuntu Touch, a wider development of free Linux operating systems specifically for mobile devices was only really spurred in the latter 2010s, when various smaller companies started projects to develop open source phones.
postmarketOS
postmarketOS (abbreviated as pmOS) is an operating system primarily for smartphones, based on the Alpine Linux distribution.postmarketOS was launched on 26 May 2017 with the source code available on GitHub before migrating to GitLab in 2018. It is capable of running different X and Wayland based user interfaces, such as Plasma Mobile, MATE, GNOME 3, and XFCE; later updates added support for Unity8 and Phosh. It is also capable of running Docker, if the device specific kernel has cgroups and relevant configs enabled. The project aims to provide a ten-year lifecycle for smartphones.