When deploying OPL-1 modules (for example, on Odoo.sh ), users must ensure the source code is kept in private repositories to prevent unauthorized public access or distribution.
Understanding the Open Publication License (OPL-1.0) The is an early copyleft free documentation license released on June 8, 1999, by the Open Content Project. Designed specifically for text, books, and educational materials, it predates the widespread adoption of Creative Commons. While largely superseded by modern licensing frameworks, it remains a milestone in open-content history. Quick Reference Summary Description Release Date June 8, 1999 Created By Open Content Project License Type Copyleft / Free Documentation Primary Target Written works, documentation, and textbooks Current Status Deprecated (Replaced by Creative Commons) Core Permissions and Rights
The is the standard license governing paid applications and themes on the Odoo Apps Store , as well as certain proprietary modules developed by Odoo S.A .. Unlike the open-source LGPLv3 used for the Odoo Community edition, OPL-1 is a proprietary license that strictly regulates the use, modification, and redistribution of software. Key Provisions of OPL-1 opl-1 license
Users may distribute sections or fragments of the text.
If you choose OPL-1, you lock your project into an island. You cannot use any popular library under MIT, GPL, or Apache. You can only use libraries that are also under OPL-1. Since OPL-1 is rare, this is effectively a non-starter for most modern web or mobile development. When deploying OPL-1 modules (for example, on Odoo
Developers are allowed to create new modules that depend on an OPL-1 module (using it as a library) without copying its source code. These new derivative modules can be distributed under any compatible license, including LGPL or other proprietary terms. OPL-1 vs. Other Odoo Licenses OPL-1 (Odoo Apps) LGPLv3 (Community) OEEL-1 (Enterprise) Type Proprietary Open Source (Copyleft) Proprietary Cost Usually Paid Subscription-based Modification Allowed for private use Allowed for partners/subscribers Resale Allowed (with conditions) Important Considerations for Developers KnowSystem: Custom Fields - Odoo Apps Store
The license permits translation, compilation, and modification. Requirements for Modified Works While largely superseded by modern licensing frameworks, it
The Open Publication License v1.0 grants users broad freedom to interact with licensed material.
| Feature | GPL (v2/v3) | OPL-1 | | :--- | :--- | :--- | | | GPLv2/v3 allows linking with proprietary software only under specific exceptions (e.g., Classpath exception) or if it's a "system library." | OPL-1 is ambiguous but generally interpreted as prohibiting linking with proprietary code unless that code is also OPL-1. | | Binary Distribution | You can distribute binaries without source if you provide a written offer valid for 3 years. | You cannot distribute binaries without immediate, full source. | | Patent Grant | GPLv3 has an explicit patent grant. GPLv2 does not. | OPL-1 has no patent grant. This is a major weakness. | | Anti-Tivoization | GPLv3 explicitly prevents hardware restrictions (Tivoization). | OPL-1 is silent on hardware; it predates the issue. | | Compatibility | GPL is compatible with many other GPL-family licenses. | OPL-1 is incompatible with GPL due to clause differences. |
Often confused with other similarly named licenses (such as the Open Software License or the Academic Free License), the OPL-1 represents a specific moment in the evolution of open source: a time when legal scholars were actively experimenting with how to enforce attribution and responsibility through contract law rather than just copyright law.
In the sprawling ecosystem of open-source software, licenses are the bedrock of collaboration. When developers hear "open source," they typically think of the MIT License, the GNU General Public License (GPL), or the Apache License 2.0. However, there is a quieter, less-discussed category of licenses that serves a specific niche for those wary of proprietary "lock-in" but distrustful of the complexity of the GPL family.