I find that thoroughness to be what's most impressive about this stack, considering every layer and securing it both independently and in relation to the others: it's as close to a textbook example as I can imagine. After all, what's the point of securing up the stack if you can't trust the bottom? Here's hoping AWS and Microsoft get there too.
Edit: Just trawling through, seems like quite a few of the tools are on github.com/google
Edit: Just trawling through, seems like quite a few of the tools are on github.com/google