Morbstack
A native macOS Docker Desktop replacement: stock upstream dockerd in one Virtualization.framework VM, a Rust PID 1, and a SwiftUI app. Pre-release.
The Docker you wish Docker shipped.
Morbstack is a native Mac app for Apple silicon that runs the real Docker Engine. It doesn't reimplement Docker: it downloads the static upstream dockerd, containerd, runc, docker CLI, Compose and Buildx, pins them by hash, and runs them unmodified inside one lightweight Linux VM on Apple's Virtualization.framework. Everything around the engine is new: a Rust PID 1 in the guest, a Swift host daemon, a morb CLI and a SwiftUI app. No account, no Electron.
It's pre-release (the project calls it milestone M0). There's no DMG yet, so you build it from source.
How it fits together
The Swift daemon owns the VM and relays the Docker socket to the guest over vsock. Inside, morbinit, a static Rust PID 1, brings up networking, the data disk, VirtioFS mounts at the same paths as on your Mac, split DNS for host.docker.internal, and Rosetta for amd64 images, then supervises stock dockerd.
The best story is port publishing. The first version shipped a 174-line patch to Moby so docker run -P could allocate ports on the Mac. A refactor on 4 August deleted it: dockerd now starts with its own --userland-proxy-path flag pointed at morbinit, so every published port is leased back to the Mac through a hook upstream already ships. The engine stays byte-for-byte upstream.
The Disk screen finally answers "why is Docker eating my disk": 77 GB reserved, 6.6 GB actually used.
A way out, and a careful way in for agents
Leaving is a first-class command. morb migrate --to copies images and volumes out to Docker Desktop, Colima, OrbStack or any socket, and verifies each copy. The Migration screen shows a read-only plan before anything moves.
morb mcp lets an AI agent drive containers, and its design doc starts from "assume the caller can be influenced by input it did not originate." It's read-only by default, every mutating tool belongs to a permission group checked on one call path, deny always wins, and a test pins the list of ungated tools by name so a new tool registered without a group fails CI. There's an audit log and redaction too.
How it was built
About 490 commits over six days (2 to 7 August 2026), with a team of specialised agents: an engine developer, a macOS developer, a parity tester and a taste reviewer. The docs are unusually blunt about themselves: a live parity audit, a "truthfulness pass" that rewrote docs whose claims had outrun the code, and a screenshot gallery that names its own visual defects.
The newest work, including the screenshot gallery, lives on the swarm/cleanup branch, which isn't merged into main yet. Apache-2.0. Not affiliated with Docker or OrbStack, despite the name.