Waymo, Cruise, Zoox, Pony.ai, Baidu's Apollo, Argo.ai and Aurora all have/had very similar approaches to the technology. Tesla is the major outlier and they haven't accomplished much in spite of the hype.
It's a product area that is very far from being able to horizontalize. Waymo Driver is going to run on Waymo hardware for a long time to come. Toyota is supposedly trying to use Waymo technology for personal vehicles. I expect adapting it will take years. The software is nothing like an app running on an operating system. All of these systems probably require years of effort to move them to a different hardware platform.
I'm curious to know where you get information on stuff like this. The Google self-driving car project was fairly transparent in the early days but since things have gotten competitive everybody is pretty tight-lipped about the particulars of what they're doing.