Re:Firefox is back. It's time to give it a try
by dreamer_ on Thursday June 21, 2018 @05:02AM
(#17363335)
Work on WebRender started before Vulkan API was widely available (even now there are lots of users, that can't use it) and right now they focus on integrating it in Firefox. Vulkan support is kept to be implemented "later", as it should enable further opportunities for parallelization in future.
https://moltengl.com/moltenvk/
https://www.khronos.org/vulkan/