No, gVisor is from Google. They emulate system calls in user-space and use VMs, which increases runtime performance overhead. We use hardware virtualization to directly run containers -- no I/O emulation, no expensive VM exits, scale as needed. Initial comparison with FC/GVisor/Xen here: https://github.com/ashishbijlani/kwarantine
Thanks for the poke on this. I had looked briefly and become frustrated that many of the instructions I found assumed you were a kernel dev and started with compiling everything from source— the Debian-supplied UML binaries seem to work well for my needs though, and do indeed allow doing basic stuff like mounting a disk image so you can run install-grub on it.