LineageOS is a free and open-source operating system for set-top boxes, smartphones and tablet computers, based on the Android mobile platform. It is the successor to the 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.[5][6] Since Cyanogen Inc. retained the rights to the Cyanogen name, the project rebranded its fork as LineageOS.[7]