KaiOS is a mobile Linux distribution for keypad-based mobile phones. It is designed and optimised for affordable and low-power feature phones, while retaining access to Internet services through web apps, based on the Gecko engine. KaiOS was originally forked from the former Firefox OS open-source project, and is developed by KaiOS Technologies (Hong Kong) Limited; a company based in Hong Kong, whose largest shareholder is Chinese electronics conglomerate TCL Corporation.
Currently, KaiOS was forked from Android for Gonk, so that device manufacturers and KaiOS themselves don't have to develop separate drivers for every component wanting to interact with the Gecko engine, but it cannot run Android's apps due to the lack of Android Runtime. wikipedia 