With the Moto G6 and G6 Plus slowly becoming more and more widely available, Motorola has published the kernel source code for the Moto G6 and G6 Plus. The G6 Play's source code was released in late April, but it's taken over a month on top of that for the G6 and G6 Plus's for whatever reason.
The Moto G6 goes by codename "Ali," and the G6 Plus by "Evert." The kernel source codes for these two devices will help developers create custom ROMs and recoveries, which enthusiast owners will no doubt want. If you're a developer (or you're just curious), links to the source code can be found below.