Well some of the US Navy computers still use DOS 6 and Windows NT4. Can't say which ones but they are not connected to any network and still use 3.5 floppies.
Federated consensus decouples trust from resource ownership and requires no assumptions about the rational behavior of attackers. Boscoin's consensus protocol is "modified" from Stellar's in that nodes form clusters and validate with their close peers first; it's faster but there's still the problem that there's only one central blockchain - all validations have to propagate eventually to all nodes.
