Licensing
Built to be commercially usable
A plain-language summary of how Open Terrain Engine will be licensed. Figures are indicative and subject to change — this is informational only and not legal advice.
Source-available / Fair Source — not open source
Open Terrain Engine is licensed under the Business Source License 1.1 (BUSL-1.1). The source is available to read and modify, but it is not an OSI open-source license. We describe it as source-available / Fair Source.
Free for most production use
Indicative, Unreal-style economics (subject to change): free to use in production under roughly $1M lifetime gross per title, with a commercial license — about a 5% royalty — above that. The exact threshold and rate are set in the final terms.
Each version eventually opens
Under BSL 1.1, every released version converts to Apache-2.0 roughly four years after it ships. The current, supported version stays commercially licensed; new releases start fresh clocks.
Permissive dependencies only
The engine's dependency tree is kept permissive (MIT / Apache-2.0 / BSD / Zlib / public-domain) with zero copyleft, enforced in CI — so adopting it doesn't pull copyleft obligations into your game.
FAQ
Is this open source?
No. It's source-available / Fair Source under BSL 1.1 — you can read and modify the source, but it isn't an OSI-approved open-source license.
Can I ship a commercial game with it?
Yes. Indicatively, it's free under roughly $1M lifetime gross per title, with about a 5% royalty above that. These numbers are indicative and subject to change — the final terms govern.
Will my version ever become open?
Yes — each released version converts to Apache-2.0 roughly four years after it ships. The current, supported version remains commercially licensed.
Will it pull copyleft into my game?
No. The entire dependency tree is permissive (MIT / Apache / BSD / Zlib / public-domain) and a CI gate fails the build on any copyleft license.
Where are the exact terms?
They're being finalized with counsel and will be published with the license text. Questions in the meantime: hello@openterrain.studio.
Indicative — subject to final terms. Any figures above (~$1M threshold, ~5% royalty, ~4-year conversion) are indicative and may change. The license grant and commercial agreement are still being finalized with counsel; nothing here is binding and the published license text will govern. Questions? hello@openterrain.studio.