Docker VMM (virtual machine monitor) is Docker's new, first-party virtualization layer for Docker Desktop, replacing third-party virtualization components with an engine that Docker can directly control and optimize specifically for container workloads. The public beta launched with Docker Desktop 4.86 for Mac and Windows.

Developers rarely think about the virtual machine monitor (VMM) until something goes wrong, such as when "it is slow, unstable, or holding onto your machine’s memory it should have released", says Docker.

Docker Desktop has always relied on a third-party VMM for this. Now it runs on Docker VMM, built by us from the ground up. That means we own the full stack, and we can tune every part of the engine for container workloads specifically. That translates directly to you: an engine that improves continuously, responds to developer feedback, and ships on our own schedule.

According to Docker, the new virtualization layer brings several performance, stability, and governance improvements in the latest Docker Desktop release. Container startup is now "measurably faster across the board", including on first launch, when switching between projects, and during restart recovery. File sharing between container and host is also improved, with the benefits particularly noticeable in edit-compile-test workflows. The new VMM also improves memory efficiency by returning unused memory to the host when containers are idle.

An additional benefit is better experience on Windows. Docker now owns the virtualization layer on Windows, aiming to provide Hyper-V-level isolation while delivering performance closer to WSL2.

Docker notes that the new VMM is not merely a performance upgrade, rather it is a new foundation for its runtime architecture across its products. The same virtualization engine powers Docker Sandboxes, meaning improvements to the underlying engine can benefit both traditional Docker workloads and isolated environments for AI agents. Docker says the longer-term goal is a more unified runtime spanning laptops, cloud, and on-prem, with containers, Compose applications, and AI agents sharing the same foundation.

Currently, the new VMM is included in Docker Desktop 4.86 on both macOS, where it is enabled automatically, and Windows, where it is available as an opt-in setting. Linux support is planned for the general availability (GA) release, expected at the end of October.