--- title: Docker Builds Its Own Virtualization Engine: Docker VMM... description: Docker Desktop 4.86 introduces Docker VMM, a virtualization engine Docker built in-house to replace the mix of third-party backends it previously relied on... canonical: https://daily.dev/posts/docker-builds-its-own-virtualization-engine-docker-vmm-enters-public-beta-fxccmzx5l twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Docker Builds Its Own Virtualization Engine: Docker VMM Enters Public Beta | daily.dev og:description: Docker Desktop 4.86 introduces Docker VMM, a virtualization engine Docker built in-house to replace the mix of third-party backends it previously relied on... og:url: https://daily.dev/posts/docker-builds-its-own-virtualization-engine-docker-vmm-enters-public-beta-fxccmzx5l og:image: https://api.daily.dev/og/posts/FXCcMZx5L.png og:image:alt: Docker Builds Its Own Virtualization Engine: Docker VMM Enters Public Beta og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Docker Builds Its Own Virtualization Engine: Docker VMM Enters Public Beta **[Collections](https://daily.dev/sources/collections)** · 2 min read · 7 upvotes · 0 comments ## Summary Docker Desktop 4.86 introduces Docker VMM, a virtualization engine Docker built in-house to replace the mix of third-party backends it previously relied on (libkrun on macOS, Hyper-V/WSL2 on Windows, KVM/QEMU on Linux). The engine promises faster container startup, quicker host-container file I/O, and better memory reclamation, with the biggest gains claimed on Windows, where Docker says it now matches Hyper-V-level isolation while approaching WSL2 speeds. The same engine already powers Docker Sandboxes for AI agents. Mac users on VMM are auto-upgraded, Windows users can opt in via Settings, and Linux support plus default rollout across all platforms is targeted for general availability at the end of October 2026. ## Content Docker Desktop 4.86 ships the public beta of Docker VMM, a virtualization layer Docker built in-house to replace the patchwork of third-party backends it's relied on until now: libkrun on macOS, Hyper-V/WSL on Windows, and KVM/QEMU on Linux. If you've used Docker Desktop for a while, you've probably noticed these backends never quite behaved the same way across platforms. That inconsistency is exactly what Docker VMM is meant to fix. It's a single engine designed to give the same performance characteristics whether you're on a Mac, a Windows box, or eventually Linux. ## What actually changes - **Faster startup.** Containers boot quicker because Docker controls the virtualization stack directly instead of going through a third-party layer. - **Better file I/O.** Reading and writing files between host and container is noticeably snappier, which matters a lot if you're bind-mounting large repos or working with data-heavy workloads. - **Smarter memory reclamation.** Idle containers give memory back instead of sitting on it. - **Windows gets a real upgrade.** Docker VMM targets Hyper-V-level isolation but with performance closer to WSL2, which has historically been the awkward tradeoff on Windows - you got either strong isolation or good speed, not both. The same engine also runs Docker Sandboxes, the isolated environments Docker built for AI agents. That's not a coincidence - Docker tested VMM internally on Sandboxes before rolling it out more broadly, and the company is positioning this as the foundation for one runtime that works the same on your laptop, in the cloud, and on-prem. ## Why this matters more than it might seem It's easy to read ## Questions this post answers ### What is Docker VMM and what does it replace in Docker Desktop 4.86? Docker VMM is a virtualization engine Docker built in-house, introduced as a public beta in Docker Desktop 4.86. It replaces the previously used third-party virtualization backends: libkrun on macOS, Hyper-V/WSL on Windows, and KVM/QEMU on Linux, unifying them into a single engine with consistent performance across platforms. _Teams standardizing container tooling across platforms can track engine changes like this one on daily.dev._ ### What performance improvements does Docker VMM bring compared to previous Docker Desktop virtualization backends? Docker VMM delivers faster container startup since Docker now controls the virtualization stack directly, snappier host-container file I/O for bind-mounted repos and data-heavy workloads, and smarter memory reclamation so idle containers release memory instead of holding onto it. On Windows specifically, it targets Hyper-V-level isolation with performance closer to WSL2. _Developers weighing container runtime upgrades can follow performance changes like these on daily.dev._ ### Does Docker VMM also power Docker Sandboxes for AI agents? Yes, Docker Sandboxes, the isolated environments Docker built for running AI agents, run on the same VMM engine. Docker tested VMM internally on Sandboxes before releasing it more broadly in Docker Desktop, framing it as the foundation for one runtime intended to work consistently across laptop, cloud, and on-prem deployments. _Engineers building AI agent infrastructure can keep an eye on runtime consolidation efforts via daily.dev._ ## Similar posts on daily.dev - [Docker Sandboxes and microVMs, explained](https://daily.dev/posts/docker-sandboxes-and-microvms-explained-ly8mg0oel) · InfoWorld · 17 upvotes · 0 comments --- Tags: [#microsoft](https://daily.dev/tags/microsoft), [#infrastructure](https://daily.dev/tags/infrastructure), [#windows](https://daily.dev/tags/windows), [#docker](https://daily.dev/tags/docker), [#containers](https://daily.dev/tags/containers) [View this post on daily.dev](https://daily.dev/posts/docker-builds-its-own-virtualization-engine-docker-vmm-enters-public-beta-fxccmzx5l) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Docker Builds Its Own Virtualization Engine: Docker VMM Enters Public Beta","url":"https://daily.dev/posts/docker-builds-its-own-virtualization-engine-docker-vmm-enters-public-beta-fxccmzx5l","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/docker-builds-its-own-virtualization-engine-docker-vmm-enters-public-beta-fxccmzx5l"},"datePublished":"2026-08-13T18:48:36.443Z","dateModified":"2026-09-13T19:46:40.096Z","description":"Docker Desktop 4.86 introduces Docker VMM, a virtualization engine Docker built in-house to replace the mix of third-party backends it previously relied on...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/43f7cda3d035f8a2e7ef08c4d5899b32?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/43f7cda3d035f8a2e7ef08c4d5899b32?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Collections","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Collections","logo":"https://media.daily.dev/image/upload/s--fk_6ycEi--/f_auto,q_auto/v1780996001/logos/collections?_a=BAMAMiWQ0","url":"https://daily.dev/sources/collections"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/docker-builds-its-own-virtualization-engine-docker-vmm-enters-public-beta-fxccmzx5l","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":7},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"microsoft,infrastructure,windows,docker,containers","timeRequired":"PT2M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Collections","item":"https://daily.dev/sources/collections"},{"@type":"ListItem","position":3,"name":"Docker Builds Its Own Virtualization Engine: Docker VMM Enters Public Beta"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/docker-builds-its-own-virtualization-engine-docker-vmm-enters-public-beta-fxccmzx5l#faq","mainEntity":[{"@type":"Question","name":"What is Docker VMM and what does it replace in Docker Desktop 4.86?","acceptedAnswer":{"@type":"Answer","text":"Docker VMM is a virtualization engine Docker built in-house, introduced as a public beta in Docker Desktop 4.86. 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