Yep - similar in some ways but headed towards different directions.
I am building a virtual machine to simplify/replace container infra. Ex. we run containers inside of linux VM's even in the `cloud`, resulting in managing both the vm, and the containers.
But smol machines is a lightweight, portable VM that you can package into a single portable .smolmachine file to be rehydrated on any platform, kind of like how containers are used for today.
Sandboxing happens to be a feature of virtual machines, so we are alike in being used for sandboxing.
(Not affiliated with them, just tried it out last week.)