License
Functional Source License, Version 1.1, MIT Future License
Varve is licensed under the Functional Source License, Version 1.1, MIT Future License (FSL-1.1-MIT). This is a source-available license that balances open access with the ability to sustain continued development, using fixed, predictable terms rather than a custom grant.
What FSL-1.1-MIT Means
You may use, copy, modify, create derivative works, publicly perform, publicly display, and redistribute Varve for any Permitted Purpose — which is any purpose other than a Competing Use. A Competing Use means making Varve available to others in a commercial product or service that substitutes for Varve, substitutes for another product or service we offer using Varve, or offers substantially similar functionality. Permitted Purposes specifically include:
- Use Varve for any purpose — personal, commercial, or educational
- Modify the source code
- Share copies of the software with others
- Study how the software works
- Develop plugins and extensions
- Redistribute your modifications, provided you keep the license notices intact
Competing uses — offering Varve (or a substitute for it) as a commercial product or hosted service to others — require a separate commercial license.
Two-Year Conversion to MIT
Each release of Varve automatically converts to the MIT licenseon the second anniversary of its first public availability. This means:
- All code eventually becomes fully open-source under the permissive MIT license
- If development stops, previously released versions become MIT-licensed over time
- The community can freely fork and continue development on MIT-licensed code
Open-Source Engine Crates
Several reusable engine crates are published separately underMIT OR Apache-2.0 — genuine OSI-approved open source licenses. These include the geometry core, colour science, auto-tracing, layout, media decoding, effect kernels, upscaling, and background removal crates.
The open crates are building blocks, not the product. The editor, document model, UI, AI features, and all application-specific code remain under FSL-1.1-MIT. See themixed-license model for the full picture.
User Rights Summary
| Use for personal projects | Allowed |
|---|---|
| Use for commercial work (client designs) | Allowed |
| Use within your organisation | Allowed |
| Modify source code | Allowed |
| Distribute official binaries | Allowed |
| Distribute modified source code | Allowed |
| Develop and sell plugins | Allowed |
| Competing use (substitute product or service) | Requires license |
| Offering as a competing hosted service | Requires license |
| Removing Varve branding | Requires license |
Contributions
Contributions to Varve are accepted under FSL-1.1-MIT (and subsequently the MIT change license after two years). Contributors retain copyright to their work. See the contribution guidelines for the project's current status on external contributions.
Third-Party Components
Varve includes third-party software under its own license terms. Full attribution is provided in the THIRD_PARTY_NOTICES file in the repository. Key components:
- Lucide icons — ISC License
- Tabler icons — MIT License
- Phosphor icons — MIT License
- Geist font — SIL Open Font License 1.1
- IBM Plex Sans font — SIL Open Font License 1.1
- ONNX Runtime — MIT License
- ONNX AI models (u2netp, Real-ESRGAN) — MIT and BSD-3-Clause
Copyright
Copyright 2024-2026 K-Arthur (Varve Founder).
"Varve" is a trademark of K-Arthur. See theTrademark Policy for usage guidelines.