LineageOS, also known as LineageOS Android Distribution and Lineage is a free and open-source operating system for smartphones and tablet computers, based on the Android mobile platform. It is the successor to the highly popular custom ROM CyanogenMod, from which it was forked in December 2016 when Cyanogen Inc. announced it was discontinuing development and shut down the infrastructure behind the project. Since Cyanogen Inc. retained the rights to the Cyanogen name, the project rebranded its fork as LineageOS.
LineageOS offers features and options not found in the official firmware distributed by mobile device vendors. Features supported by LineageOS include native theme support, FLAC audio codec support, a large Access Point Name list, Privacy Guard (per-application permission management application), support for tethering over common interfaces, CPU overclocking and other performance enhancements, unlockable bootloader and root access, soft buttons, status bar customisation and other “tablet tweaks”, toggles in the notification pull-down (such as Wi-Fi, Bluetooth and GPS), and other interface enhancements. LineageOS does not contain spyware or bloatware, according to its developers. It is also said to increase performance and reliability compared with official firmware releases.