GVisor

gVisor is a container sandbox developed by Google that focuses on security, efficiency and ease of use. gVisor implements around 200 of the Linux system calls in userspace, for additional security compared to Docker containers that run directly on top of the Linux kernel and are isolated with namespaces. Unlike the Linux kernel, gVisor is written in the memory-safe programming language Go to prevent common pitfalls which frequently occur in software written in C.

According to Google and Brad Fitzpatrick, gVisor is used in Google's production environment including the App Engine standard environment, Cloud Functions, Cloud ML Engine and Google Cloud Run. Most recently, gVisor was integrated with Google Kubernetes Engine, allowing users to sandbox their Kubernetes pods for use cases like SaaS and multitenancy.