The Modtale Public Source License (MPSL) is a strong copyleft license that requires source code disclosure for derivatives and network use, while restricting binary distribution exclusively to the Modtale Platform.
Copyright © 2026 Modtale Project and Contributors. All rights reserved.
MPSL is designed for adoption by any project. It balances open collaboration with controlled binary distribution tied to the Modtale Platform.
It allows anyone to:
- Use the source code
- Modify the source code
- Fork the project
- Distribute source code and derivatives
It requires that:
- All derivatives remain licensed under MPSL v1.0
- Complete corresponding source code is made available
- Network deployments provide public access to source code
- Modified files include prominent notices of changes
It restricts that:
- Compiled binaries may only be distributed through the Modtale Platform
- No external mirrors, app stores, repositories, automated build systems, hardware bundling, or third-party binary distribution are allowed
Copyleft All forks and derivative works across the entire Fork Chain must remain under MPSL v1.0.
Network Use Clause If you run a modified version over a network (API, server, hosted service), you must provide users with immediate access to the full corresponding source code.
Platform-Locked Binaries Compiled binaries may only be distributed via the official Modtale Platform (modtale.net or a successor domain officially designated by the Modtale Project).
Private Use Exception You may compile and use binaries privately, but you may not share them outside your private environment.
Sunset Clause If the Modtale Platform becomes defunct for 60 consecutive days, the binary distribution restriction permanently terminates and binaries may then be freely distributed under the remaining terms of the license.
Root Project Governance Relicensing authority and governance are exclusively tied to the Root Project that first adopted MPSL. Downstream forks do not have independent relicensing authority.
Relicensing Authority Only the Lead Maintainer of the Root Project may relicense the Software, across the entire Fork Chain, under AGPL-3.0, GPL-3.0, or MIT.
Patent Grant and Termination The license includes an express patent grant and terminates patent rights for parties who initiate patent litigation related to the Software.
All contributions are governed by the included Contributor License Agreement (CLA).
Contributors retain copyright but grant rights under MPSL v1.0 and grant exclusive relicensing authority to the Lead Maintainer of the Root Project.
See the LICENSE file in this repository for the complete legal text of MPSL v1.0, including definitions of Root Project, Fork Chain, Lead Maintainer authority, dispute resolution, and enforcement provisions.
The Software is provided "as is", without warranty of any kind. See the full license text for complete terms and limitations.