Spine Licensing Policy

Status

This document records the intended licensing policy for Spine as an open language and verification platform with a Foundation-governed public core and a commercial value-added layer.

Unless superseded by a future Foundation resolution, this repository adopts the following default:

• core Spine code: Apache License 2.0,
• specifications and governance text: Apache License 2.0 unless stated otherwise,
• examples and templates: Apache License 2.0 by default,
• trademarks: reserved and governed separately from copyright licensing.

Why Apache License 2.0

Apache License 2.0 is the right default for Spine because it preserves all of the following at once:

• strong open adoption,
• commercial usability,
• a clear patent grant,
• compatibility with a Foundation-governed public core,
• room for proprietary Pro, Enterprise, hosted, and marketplace offerings that add workflow value without owning the meaning of the language.

Spine is a language platform, not merely an application. For that reason, the patent grant matters materially. Apache License 2.0 is better aligned than MIT with long-term language and tooling stewardship.

Policy Goals

The licensing model must support these constraints:

• one semantic Spine across Community and paid editions,
• open standards for models, packages, registries, provenance, and compatibility,
• low-friction academic, industrial, and enterprise adoption,
• the ability for a commercial entity to monetize better participation rather than semantic control,
• long-term Foundation legitimacy.

License Matrix

Foundation-Governed Community Core

The following should be Apache License 2.0:

• language specification sources,
• compiler and verifier core,
• Community standard library,
• reference CLI,
• baseline Community LSP support,
• conformance suites and compatibility rules,
• public registry and package protocol specifications,
• model/package metadata schemas.

Open Documentation

Unless a future standards process chooses otherwise, project documentation should also remain under Apache License 2.0 for simplicity.

If the Foundation later wants standards-style text reuse with clearer document attribution rules, it may migrate some specification prose to CC BY 4.0. That is optional, not required now.

Paid Products and Services

The following may remain proprietary:

• Spine Pro,
• Spine Enterprise,
• hosted services,
• premium LSP and MCP features,
• persistence, learning, and organizational memory systems,
• commercial marketplace operations,
• enterprise governance, audit, and policy tooling,
• support and integration assets not designated as Community.

These products may improve workflow, scale, collaboration, and convenience, but must not redefine the public semantics of Spine.

Excluded Strategies

The following are not recommended for the public Spine core:

• GPL or AGPL as the default core license,
• source-available licenses such as SSPL, BSL, or Elastic-style field-of-use restrictions,
• proprietary licensing of the language standard, compiler semantics, or public protocol surface.

Those approaches conflict with the intended Foundation settlement and make the commercial layer look like semantic capture rather than value addition.

Repository Rule

The repository root license applies by default unless a subdirectory contains a different license file for vendored or separately governed material.

Contributor Rule

Contributions are accepted under an inbound equals outbound model.

In practice:

• the project accepts contributions under Apache License 2.0,
• contributors should sign off commits under the Developer Certificate of Origin model,
• trademark rights are not granted by code contribution.

Governance Link

This policy is meant to implement the principles laid down in:

• Ecosystem Constitution
• Foundation Charter Appendix

Summary

License the truth of Spine openly. Monetize the quality of using Spine commercially.

That is the licensing rule this policy is designed to preserve.