The Moto X Pure (code name Clark, apparently) is still just starting to arrive on doorsteps, but Motorola has pushed the open source code to GitHub for all interested parties to start tinkering with. This follows the release of Android 5.1 source for the 2014 Moto X back in July and the new Moto G in August.
This is more news for developers than regular users, but you might still benefit from it down the road. Getting the kernel source is an important step in the process of creating properly optimized apps and mods. The code is based on Android 5.1.1 and is 145MB in size.