After much anticipation, Microsoft launched its very first Android device last month. In Corbin's review, he called it a phone for enthusiasts, and that's something Microsoft seems to be embracing. Microsoft has released the Surface Duo's kernel source, which will assist third-party developers in building custom ROMs and kernels for the unique device.
Since Android devices are built around Linux kernels distributed under an open-source license, manufacturers are required to release the underlying code upon request. Needless to say, some are better at it than others. Microsoft publishing the kernel early on will help the Android development community create custom ROMs and kernel tweaks for the device that much faster.
Microsoft got off to a good start in sharing details about what makes the Duo tick when gave us an extensive look at the wiring inside last month. It's also one of the few Android OEMs to commit to 3 years of major OS upgrades and ship the device with a fully-unlockable bootloader. Heck, it even published a guide for building the kernel alongside the codebase. If you're a developer (or just curious), you can take a gander at the kernel source code yourself over on Microsoft's GitHub repository.