BorgMaster had its own consensus protocol prior to paxos lib. It was switched to paxos in 2010? (Don't quote me on this)

Chubby uses paxos. Iirc, the history is that Chubby comes first, then it's paxos code got pulled out into paxos lib, which proliferate inside Google.

And yes, Google had no other choice than Paxos at its days.