Modular Cooperative License

The Modular Cooperative License, or MCL, is a modular software license framework. In v1.1.1, it can be configured from a permissive, MIT-like floor to profiles that are more restrictive than AGPLv3. Optional modules let a Licensor choose how aggressively the license responds to distribution, file-level reciprocity, SaaS use, cloud binary publication, patent retaliation, temporary security coordination, staged preview publication, internal-use reciprocity, anti-shim behavior, commercial competition, alternative licensing, contributor intake, and optional AI training restriction.

The canonical license text in this repository is MCL-LICENSE. Annex A lets the Licensor choose the exact posture.

What MCL is for

MCL is designed for projects that want more precision than a conventional copyleft license usually gives them. Its text focuses on the places where modern software businesses tend to create ambiguity, including:

• sham plugin boundaries
• hosted wrappers around reciprocal code
• cloud-only deployment artifacts
• private fork cycling
• control-plane gating
• selective publication of source without meaningful operational materials

The goal is not to absorb every adjacent system. The goal is to draw stronger, clearer lines around the systems that are functionally part of the same covered work.

How MCL is structured

MCL has two layers:

• Base Terms in Clauses 1 through 10
• Optional Modules activated in Annex A for the relevant version, distribution, deployment, or release

In practice, that means the same base license text can support several policy profiles without forcing every project into the same posture. With no modules activated, v1.1.1 is the permissive floor. Activating MOD-FILE restores a weak file-level reciprocity baseline, and stronger modules push further from there.

Annex B includes example presets, but the actual legal effect always comes from the completed activation block in Annex A.

Module summary

Module	Purpose	Notable effect
MOD-AI	Restrict machine learning training use	Field-of-use restriction
MOD-BIN	Require deployable cloud artifacts and operational materials	Strong cloud publication duties
MOD-CLA	Support contributor agreements and controlled relicensing	Adds contributor intake and relicensing machinery
MOD-COM	Restrict direct substitute commercial use	Field-of-use restriction
MOD-DIST	Require full reciprocal source publication on distribution	Whole-work distribution copyleft
MOD-FILE	Require modified files to stay available under MCL on distribution	Weak or file-level reciprocity
MOD-INT-A	Permit internal use without extra public reciprocity	Internal-use safe harbor
MOD-INT-B	Require internal reciprocity for integrated internal systems	Internal sharing obligation
MOD-INT-C	Require public release of the internally used covered work	Public release of internal covered-work version
MOD-INT-D	Require public release of the internally used covered work and integrated internal systems	Strongest internal-use reciprocity
MOD-NET	Trigger reciprocity for network or SaaS operation	Public source for running network version
MOD-PAT	Add patent retaliation and stronger patent-litigation termination	Optional patent-aggression response
MOD-PLUG	Police fake extension boundaries and anti-shim behavior	Strong integral-component rules
MOD-PUB	Prevent long-lived private forks	Public fork publication clock
MOD-SEC	Allow temporary private security coordination and trusted disclosure	Deferred public publication for embargoed security fixes
MOD-STAGE	Allow temporary staged preview releases and later publication	Deferred public publication for preview branches or releases
MOD-SUB	Permit a fully authorized steward to offer alternative licenses	Explicit alternative-licensing authority

Compatibility notes

MCL is a custom license. It is not identical to GPL-3.0, AGPL-3.0, Apache-2.0, or any other stewarded license.

The no-module v1.1.1 floor is the permissive end of the framework. MOD-FILE adds weak reciprocity. Stronger modules can then push the license well beyond ordinary copyleft.

The current license text includes conditional GPLv3 and AGPLv3 compatibility bridges for qualifying activation profiles. Those bridges are unavailable when certain blocker modules are active.

Important cautions:

• MOD-COM is not open source in the OSI sense
• MOD-AI is not open source in the OSI sense
• MOD-SEC is not open source in the OSI sense
• MOD-STAGE is not open source in the OSI sense
• profiles that activate MOD-AI, MOD-BIN, MOD-COM, MOD-INT-B, MOD-INT-C, MOD-INT-D, MOD-PUB, MOD-SEC, or MOD-STAGE do not use the AGPLv3 bridge
• profiles that activate MOD-NET do not use the GPLv3 bridge, but may still use the AGPLv3 bridge if no other blocker modules are active
• MOD-CLA, MOD-DIST, MOD-FILE, MOD-INT-A, MOD-NET, MOD-PAT, MOD-PLUG, and MOD-SUB do not by themselves disable the relevant bridge, except that MOD-NET is AGPL-only for compatibility purposes
• the compatibility section in MCL-LICENSE is the governing text for actual use

How to apply MCL

1. Copy MCL-LICENSE into the root of your project.
2. Complete Annex A for the exact project and version you are licensing.
3. Activate only the modules you actually want.
4. Publish any additional materials required by the active modules, such as:
   • Corresponding Source
   • compliance records
   • Operational Materials
   • extension API documentation
   • contributor agreement materials
5. Add a repository-level or file-level notice identifying the applicable MCL version and the location of the license text.

If you want a starting point instead of a blank configuration, review the preset profiles in Annex B and then tailor the activation block for your actual policy. In v1.1.1, no modules gives you the permissive floor, while MOD-FILE gives you the weak file-level copyleft layer that older MCL drafts treated as the baseline. If you want concrete filled-out activation blocks, start from the examples in examples/.

Repository contents

• CHANGELOG.md — repository-level change history
• CONTRIBUTING.md — contribution and discussion guidance
• MCL-LICENSE — canonical license text
• examples/ — filled-out Annex A examples for common policy postures

Legal note

This repository publishes license text and supporting documentation. It does not provide legal advice. If you plan to deploy MCL for real software or high-value intellectual property, you should have the text reviewed by qualified counsel in relevant jurisdictions.