"Ahead of the Vulkan 1.0 debut nearly two years ago, we heard
that for AMD's Vulkan Linux driver it was initially going to be
closed-source and would then be open-sourced once ready. At the time it
sounded like something that would be opened up six months or so, but
finally that milestone is being reached! Ahead of Christmas, AMD is
publishing the source code to their official Vulkan Linux driver."