Interesting indeed. The last I looked, Hurd was pretty limited to 32 bit address spaces, and with 2GB [2^31] limitations here and there, as it's tough to get Mach development to keep up with the new hardware getting released. I didn't think there was a 64 bit Mach, at least not supported ... The notable hope would be in running Hurd virtualized, so that its limitations become less restrictive as they may often be practically overcome by running multiple instances. Anyone familiar with where things stand on running Hurd on modern-ish hardware?