1VMTool vs Tart
These two share a foundation — both clone disks with APFS instead of copying them — and then build completely different products on top. This is the closest technical comparison on the list.
Side by side
| 1VMTool | Tart | |
|---|---|---|
| Snapshot mechanism | APFS clone with a branching snapshot tree, restore and rollback mode. | Clone is the snapshot — the same APFS primitive, without a snapshot tree. |
| Interface | GUI and CLI as peers. | CLI only, and the best in this niche. |
| CI workflow | No image registry integration. | OCI registries as image storage, plus Packer and Orchard. |
| Windows guests | Experimental first-party engine. | None. |
| macOS guests | Supported. | Supported, and the tool of choice for CI images. |
| Bundled dependencies | None. | None. |
| License clarity | Commercial, one-time. | Fair Source (FSL-1.1-ALv2) under OpenAI — settled terms, unproven maintenance. |
| Price on one Mac | One-time purchase. | Free. |
Highlighted cells mark the stronger side of each row. Competitor details checked September 2026 against vendor documentation — pricing and features move, so verify anything decision-critical at the source.
When you should stay on Tart
You run macOS CI. Pulling an image from a registry and running it is a loop Tart is genuinely better at than 1VMTool, and it is deployed widely for exactly that. If you are a CI engineer, stay.
Where Tart frustrates people
- There is no GUI by design — no machine library, no snapshot tree, no storage view.
- No Windows guests, because it stays inside Virtualization.framework's device model.
- Ownership moved to OpenAI in 2026 and the license settled into Fair Source — clearer terms, but the original team moved on and long-term maintenance under the new owner is unproven.
- macOS guest disk resizing and recovery-partition handling still involve documented rituals that are fine for CI images and tedious for a desktop machine.
Why someone moves to 1VMTool
- You want a GUI: a machine library, a snapshot tree, a console window and host metering.
- You want Windows on ARM, which Tart does not offer.
- You want a branching snapshot tree and rollback mode rather than clone-as-snapshot.
- You want licensing you do not have to re-check before rolling it out.
Frequently asked questions
Tart already does instant APFS clones — why 1VMTool?
The same disk primitive, a different product. Tart is CI and OCI images. 1VMTool is a desktop app with a snapshot tree, rollback mode, host metering and a Windows engine. If you live in macOS CI runners, stay on Tart.
Can Tart run Windows 11 on ARM?
No. It stays within Virtualization.framework's device model, and the maintainers have said so. 1VMTool added a second engine specifically to get past that limit.
Is Tart still free after the ownership change?
For non-competing use, yes — it is now Fair Source (FSL-1.1-ALv2) under OpenAI and converts to Apache 2.0. The old Cirrus Labs core-count tiers are no longer the stated license, though the public licensing page still describes them, so read the current text before a wide rollout.
Try it against your own workflow
The limits are stated on every screen before you commit to anything, which is the fastest way to find out whether this is your tool.