ASUS recently unveiled its 2019 flagship ZenFone 6, and this phone marks quite a shift for the company. Its bezel-less, notch- and cutout-free display brings it on par with the OnePlus 7 Pro, and the flipping back camera is an interesting solution. Coupled with its stock Android experience, the phone is bound to attract some enthusiasts. Now, the company has also released the device's kernel source and unlock tool, making it even more interesting for that demographic.
ASUS has published a support website where interested customers can download both the bootloader unlock tool and the source code. Be wary that unlike with other manufacturers, you can't revert to a locked state, and your warranty will be void once you've finished the procedure. You also won't receive official OTA updates from ASUS anymore, but you should still be able to flash new software manually. Still, I'd advise only to unlock the bootloader if you're absolutely sure that you're going to use or develop a custom ROM for the device and that you don't want to stick to ASUS's software.