Modular Project License System (MPLS)

A composable, SPDX-compatible licensing framework that allows projects to define permissions, restrictions, and monetization models by selecting clauses instead of rewriting licenses.

MPLS is designed for:

• Personal / non-commercial projects
• Dual licensing (free + paid commercial)
• Donationware
• Open-source (MIT/GPL-style)
• AI, SaaS, libraries, research, and tooling

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Why MPLS?

Traditional licenses are rigid. Modern projects need flexibility.

MPLS solves this by:

• Using modular legal clauses
• Supporting monetization by design
• Remaining SPDX-compatible
• Being machine-readable & generator-friendly

One base system. Infinite license combinations.

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Core Principles

• Modular – Licenses are built from reusable clauses
• Minimal – Only explicitly enabled permissions apply
• Clear – No hidden rights, no ambiguity
• Composable – Mix non-commercial, paid, OSS, donation clauses
• Automatable – Generate licenses programmatically

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SPDX Compatibility

MPLS uses valid SPDX custom identifiers:

LicenseRef-MPLS
LicenseRef-MPLS-NC-1
LicenseRef-MPLS-DUAL-1
LicenseRef-MPLS-DON-1
LicenseRef-MPLS-OSS-MIT
LicenseRef-MPLS-OSS-GPL

Clause-level identifiers are also supported internally:

LicenseRef-MPLS-Clause-U1
LicenseRef-MPLS-Clause-P1
LicenseRef-MPLS-Clause-D4

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License Structure

Each MPLS license consists of:

1. SPDX Identifier
2. Enabled Clause List
3. Legal Text for Each Clause
4. Warranty & Liability Disclaimer

Any permission not explicitly granted is prohibited.

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Clause Categories

Usage

• Personal
• Educational
• Commercial (allowed or prohibited)

Payment

• Free
• One-time fee
• Subscription
• Donationware

Distribution

• No redistribution
• Redistribution allowed
• Modification allowed
• Copyleft enforcement

Source Code

• Closed distribution allowed
• Source disclosure required

Attribution & Branding

• Attribution required or optional
• Trademark restrictions

Warranty & Liability

• No warranty
• No liability

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Predefined License Profiles

MPLS-NC-1 (Personal / Non-Commercial)

Free for personal and educational use. Commercial use and redistribution are prohibited.

SPDX-License-Identifier: LicenseRef-MPLS-NC-1
Clauses: U1, U2, U3, P0, D1, S1, A1, W1, W2

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MPLS-DUAL-1 (Dual License)

Free for non-commercial use. Commercial use requires a paid license.

SPDX-License-Identifier: LicenseRef-MPLS-DUAL-1
Clauses: U1, U2, U3, U4, P1, D2, S1, A1, W1, W2

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MPLS-DON-1 (Donationware)

Free to use with optional donations.

SPDX-License-Identifier: LicenseRef-MPLS-DON-1
Clauses: U1, U2, U4, P3, D2, S1, A1, W1, W2

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MPLS-OSS-MIT (Permissive Open Source)

Equivalent to MIT-style licensing.

SPDX-License-Identifier: LicenseRef-MPLS-OSS-MIT
Clauses: U1, U2, U4, P0, D2, D3, S1, A1, W1, W2

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MPLS-OSS-GPL (Copyleft Open Source)

Equivalent to GPL-style licensing.

SPDX-License-Identifier: LicenseRef-MPLS-OSS-GPL
Clauses: U1, U2, U4, P0, D2, D3, D4, S2, A1, W1, W2

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License Generator

A minimal Python-based generator is included.

Example

python generate_license.py > LICENSE.md

Generator Inputs

• SPDX Identifier
• Clause ID list

The generator outputs a complete, legal-grade license file.

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Recommended Repository Layout

/
├── LICENSE.md
├── README.md
├── generate_license.py
└── licenses/
    ├── MPLS-NC-1.md
    ├── MPLS-DUAL-1.md
    └── MPLS-OSS-MIT.md

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Best Practices

• Always include SPDX-License-Identifier at the top of files
• Clearly summarize the license in README.md
• Use predefined profiles where possible
• Avoid mixing contradictory clauses

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Disclaimer

MPLS is provided as a licensing framework. You are responsible for ensuring compliance with local laws and regulations.