Licensing
Mantle is free to self-host and run for your own use under the Functional Source License (FSL-1.1-MIT). A paid commercial license is needed only to sell it or build it into a product that competes with it.
What you may do without paying
The license allows any purpose except a competing use. That includes:
- running Mantle for yourself or inside your company;
- non-commercial education and research;
- professional services for someone who uses Mantle under the same license.
You may use, copy, change and redistribute the code for these purposes.
What needs a commercial license
A competing use: offering Mantle, or something that does substantially the same job, to others as a commercial product or service. Two common cases:
- Embedded use: shipping Mantle’s code, APIs or database schema inside your own paid software.
- Competing service: hosting Mantle and selling access to it.
For a commercial license, email licensing@crossworks.engineering.
Each version becomes MIT after two years
Two years after a version is first published, that version is also available under the MIT license. Newer versions stay under the FSL until their own two years pass.
Third-party software
Mantle includes open-source packages under their own licenses, mostly MIT and Apache 2.0. Every license text is in THIRD-PARTY-NOTICES.md in the repository.
The legal texts
This page is a summary. Where it differs from the license files, the files apply.
LICENSE.md: the full FSL text.LICENSE-COMMERCIAL.md: the commercial agreement.LICENSING.md: a plain-language explainer.
The Jackdaw interface is licensed the same way, with the same files in its own repository.