Developer Mike Blumenkrantz has announced that they're now being funded by Valve, so Blumenkrantz's work on the OpenGL implementation on top of Vulkan with 'Zink' will continue.
Hold on, what actually is Zink? As described by Collabora dev Erik Faye-Lund it's an "OpenGL implementation on top of Vulkan. Or to be a bit more specific, Zink is a Mesa Gallium driver that leverages the existing OpenGL implementation in Mesa to provide hardware accelerated OpenGL when only a Vulkan driver is available".
After working on Zink for a while, Mike Blumenkrantz posted a blog entry back on November 6 saying it was the "last day" due to the end of it being hobby work while being between jobs. In a new blog post titled "Don't Call It A Comeback", Blumenkrantz mentions that "Valve has generously agreed to sponsor my work on graphics-related projects" and that the focus will be on Zink.
The plan for Zink is a big one and things are moving quickly. Working together with Collabora developer Erik Faye-Lund, together they're doing "Operation Oxidize" to get the majority of their work in progress code for Zink into mainline Mesa by the end of the year. This will give Zink basic OpenGL 4.6 and OpenGL ES 3.2 support along with "vastly" improved performance.
Nice to see Valve continuing to get involved with open source and Linux to improve all sorts of areas.
For those curious on the question of why — well, Vulkan is the future. This video can explain it in more details: