It's a Nonprofit Public Benefit Corporation. So that means it must have raised $500k from other people, each of which cannot have given more than $30k. That's pretty impressive. I wonder who the other sponsors were.
In terms of SWE, it doesn't get harder than an OS in my book (and not even from scratch). So them coming from success in that space is more than enough to convince me they can deliver a world-class browser core engine.