Those of you familiar with the GPL will know that manufacturers are required to post any modifications they make to the Android kernel. Motorola does this with all of their phones, including the Nougat-powered Moto X4, but now that Oreo is out for the phone (well, at least the Android One version), the source code for that needs to be posted as well. Lo and behold, it has.
A developer requested the kernel source code for the X4 (codenamed 'payton') about two weeks ago in Motorola's GitHub, and it's finally been granted. Now that the source code is available, developers will be able to whip up some of your favorite custom ROMs on the Moto X4 in Oreo flavor more quickly and with fewer issues.