License
Two-tier model — open tooling under MIT, dsviper runtime under a dual-mode commercial license.
Two-tier model
Tooling — MIT
Kibo, kibo-template-viper, dsviper-tools, dsviper-components (Qt Widgets and QML variants), and dsm-samples are released under the MIT License. Free for any use, including commercial — no agreement required.
dsviper runtime — Commercial license, two modes
The Python runtime is published on PyPI under the Digital Substrate Commercial License 1.2. Two modes apply: free Evaluation, or signed Commercial agreement for production. Detailed below.
Viper C++ engine — by request
The C++ foundation that powers dsviper is not published on a public channel, but access can be arranged on request — get in touch to discuss your use case.
dsviper runtime — license modes
Evaluation License
Free
Unlimited duration. Non-commercial.
Permitted
- Evaluating fit for your workflow
- Training and learning
- Sharing results with a limited number of third parties — free of charge, no commercial benefit
- Filing issues and contributing pull requests
Not included
- Any commercial use, direct or indirect
- Use in negotiations, tenders, or commercial transactions
- Modification (use only as distributed)
- Redistribution or sublicensing
- Support, maintenance, or updates
Commercial License
By agreement
Tailored to your deployment. Signed agreement required.
Permitted
- Production deployment
- Integration into proprietary projects and products
- Modification, redistribution, sublicensing — as defined in the Agreement
- Support and maintenance — per Agreement
- Updates within the LTS-1.2 line
How it works
- Signed agreement with Digital Substrate, scoped to your deployment — seats, support level, custom templates, integration, training.
- Conversion from Evaluation is straightforward — no reinstall.
Frequently asked questions
What counts as "commercial use" under this license?
Direct or indirect commercial benefit — including use in negotiations, tenders, or commercial transactions. If your intended use is not pure evaluation or training, contact us to confirm whether a Commercial License is required.
Can my company evaluate DevKit internally before signing a Commercial License?
The Evaluation License explicitly covers assessment for fit with your workflow and training. Internal evaluation in that scope is permitted. The boundary between "evaluation" and "internal commercial use" is one we are happy to discuss case by case — please reach out.
I'd like to fix a bug or contribute a feature — what's the process?
For the MIT-licensed tooling, open an issue or a pull request on the relevant repository under github.com/digital-substrate — MIT terms apply. For the dsviper runtime, the source is not published; report bugs and feature requests by contact.
What about Qt and other third-party dependencies?
The dsviper runtime statically links four third-party components (ANTLR 4, a hash library, nlohmann/json, SQLite); their notices are bundled in the wheel. The Python GUI tools (dsviper-tools, dsviper-components) use PySide6 — Qt is dynamically linked under LGPL v3 there. See the Legal page and the canonical documentation for details.
Ready to discuss?
Tell us about your project and we will come back with a tailored proposal.
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