[mundo]

I think KBFS is a sort of an add-on to Keybase, which is really quite different from this. Keybase's whole schtick is identity and key management. How do share a file with a stranger without exchanging emails? What happens when you lose the email you signed up with? How do you share keys between your devices without trusting a for-profit company's keystore? Keybase solves those for you, and IMHO is quite novel and useful.

Upspin is a separate thing that focuses entirely on how files should be stored and identified, and (AFAICT) does nothing new regarding identity management. Which is unfortunate, because that seems like the more urgent problem right now.