Technically, there are vendors other than Google. Red Hat have an implementation called CapeDwarf. There's also AppScale. There was another called TyphoonAE, bu

Technically, there are vendors other than Google. Red Hat have an implementation called CapeDwarf. There's also AppScale. There was another called TyphoonAE, but I haven't noticed any signs of life from that one in quite some time. The big unknown for me is how usable any of those implementations are, and whether there is such a thing as a decent migration path (for data) from Google to them, and vice-versa.