Moto Mods
How to start a Moto Mods?
http://developer.motorola.com.cn/
This is a simplified chinese website, but there is a small part of development document on this website.
For more detail devleopment document please visite https://developer.motorola.com/ and https://www.element14.com/community/groups/moto-mods
There is a shortcut you can contact with Moto Mods team Ask MDK Help.