Docker has always used microVMs, starting with Docker Toolbox in 2015 using VirtualBox. The goal was to make Docker Desktop feel like a native app on Mac and Windows, leading to the creation of a library VMM called hyperkit, later evolved into Docker VMM. The VM kernel and root filesystem were minimal, based on Linux Kit.
Docker for Mac launched in 2016 using this microVM approach, enabling rootless execution, minimal device exposure, and seamless VPN and network policy integration. This foundation now powers Docker Desktop and Docker Sandboxes, which allow secure execution of coding agents like Claude via `sbx run claude`. The technology remains conceptually similar to containerd/nerdbox, with ongoing improvements for efficiency and security.
Source: Hacker News · Summarized by HeadlinesBriefing