macSandbox for Windows

Disposable Windows 11 ARM64 sandbox for Apple Silicon Macs — the Windows Sandbox experience, on macOS. Boot a throwaway Windows environment in seconds from a prebuilt base image; every change is discarded on exit.

Runtime: QEMU + Hypervisor.framework (HVF) for virtualization, with an in-app embedded RDP view (libfreerdp) for display, input, clipboard, folder, printer, and audio redirection. The base image is built once from your own Windows 11 ARM64 ISO via a fully deterministic, unattended WinPE + DISM deployment — no clicks, no prompts.

Features

• Disposable by design — copy-on-write overlay per session; discarded on exit
• One-time unattended baseline build from your Windows 11 ARM64 ISO (deterministic WinPE/DISM deployment, virtio driver injection, Edge first-run experience disabled, inbox bloatware removed)
• In-app RDP session — no external windows; dynamic resolution, HiDPI (Retina) scaling, trackpad scrolling and pinch-to-zoom
• Windows Sandbox .wsb compatibility — see WSB-SUPPORT.md and examples/sample.wsb
• Clipboard (text and files, both directions), shared folders (\\tsclient auto-mount), printer redirection (CUPS), audio playback and microphone
• Localized UI — English, 한국어, 日本語, Deutsch, Español, Français; Korean/Japanese keyboard layouts (right Option = 한/영)
• License-aware — confirms Windows licensing checklist before every base image build; this project ships no Windows OS, key, or entitlement

Requirements

Apple Silicon only — Intel Macs are not supported. The runtime depends on Apple Silicon virtualization (Hypervisor.framework) and a Windows 11 ARM64 guest; there is no Intel/x86 build or path.

• Apple Silicon Mac (M1 or later) — Intel Macs are not supported
• macOS Tahoe (26) or later (recommended minimum)
• A Windows 11 ARM64 ISO you are licensed to use (e.g., from Microsoft's official download channels)
• ~24 GB free disk space during the one-time baseline build

Minimum OS note: the binary is built for macOS 14 (Sonoma) and links arm64_sonoma dependencies, so it may launch on macOS 14–15 — but only macOS Tahoe has been tested, and HVF/virtualization behavior on earlier releases is unverified. Use macOS Tahoe for a supported experience.

Building from source additionally needs Homebrew (brew install freerdp wimlib); the packaged DMG bundles these libraries, so end users running the release do not need Homebrew.

Download & install

Download the latest macSandbox-for-Windows-<version>.dmg from the Releases page, open it, and drag macSandbox for Windows into Applications.

This build is not signed or notarized (ad-hoc signature), so macOS Gatekeeper blocks it on first launch. To allow it:

1. Double-click the app — macOS blocks it ("Apple could not verify…").
2. Open System Settings → Privacy & Security, scroll down to Security, and click Open Anyway next to the macSandbox message; authenticate, then Open.

Or clear the quarantine flag from Terminal and open normally:

xattr -dr com.apple.quarantine "/Applications/macSandbox for Windows.app"

Build from source

# Development build
swift build && .build/debug/MacSandbox

# Packaged .app + DMG (bundles QEMU; see scripts/build.sh for vendor setup)
scripts/package_app.sh

On first launch the app asks for your Windows 11 ARM64 ISO and builds the baseline image unattended (one round, typically 20–40 minutes). After that, every launch boots a fresh disposable sandbox straight into an in-app RDP session.

Command-line options mirror .wsb settings:

MacSandbox my-config.wsb
MacSandbox --memory 8192 --cpus 4 --folder ~/Downloads:ro --logon "notepad"

Documentation

• ARCHITECTURE.md — how the deterministic WinPE/DISM baseline build and the QEMU + embedded-RDP runtime work
• WSB-SUPPORT.md — .wsb configuration support matrix
• Project website (GitHub Pages, served from docs/)

Licensing

macSandbox for Windows is dual-licensed:

1. GNU AGPL-3.0-or-later (open-source edition) — see LICENSE
2. Commercial license — see COMMERCIAL-LICENSE.md

Bundled third-party components (QEMU, EDK2 firmware, etc.) and linked libraries (FreeRDP/WinPR) remain under their own licenses — see LICENSING.md, THIRD-PARTY-NOTICES.md and WRITTEN-OFFER.txt. QEMU runs strictly as a separate process; do not link it in-process (see the invariant in LICENSING.md).

This project does not include Windows. You must provide your own Windows 11 ARM64 ISO and hold a valid license for each Windows instance you run. macSandbox for Windows is an independent project, not affiliated with or endorsed by Microsoft. Windows is a trademark of the Microsoft group of companies.

Contributing & Support

• Bug reports and feature requests are accepted only via GitHub Issues. There is no e-mail support channel.
• External contributions require agreeing to the CLA, which enables the project's dual-licensing model (AGPL + commercial).

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© 2026 Nam Jung Hyun (rkttu)