Really excited about this and rust-vmm which allows you to build custom Virtual Machine Monitors. The problem with a solution like Firecracker, and why they are able to get such fast startup times and a small memory footprint is that they selected a subset of features to expose. This limits the capabilities of the running container, which is of course the point. But it is not general purpose enough for all workloads. For instance, I want to use Firecracker but require host file system sharing. Rust-vmm looks like it is trying to solve this problem by providing a collection of rust crates that allow users build their own VMM with the features they need. It's build-a-bear for VMMs :)