LibreOffice Open Source License Guide

LibreOffice is primarily governed by the Mozilla Public License version 2.0 (MPL-2.0). This article explains the core principles of the MPL-2.0, detailing the rights, permissions, and obligations for individuals, organizations, and developers looking to use, modify, or redistribute the LibreOffice suite.

The Primary License: Mozilla Public License 2.0

LibreOffice adopted the Mozilla Public License v2.0 as its primary license starting with LibreOffice version 4.0. The MPL-2.0 is a free, open-source, and weak copyleft license maintained by the Mozilla Foundation. It is recognized and approved by both the Open Source Initiative (OSI) and the Free Software Foundation (FSF).

Key Permissions for Users and Organizations

Under the MPL-2.0, LibreOffice provides extensive freedom to users across all environments:

• Commercial and Personal Use: Anyone can download, install, and use LibreOffice for personal, educational, governmental, or commercial purposes at no cost.
• Redistribution: Individuals and businesses are permitted to copy and redistribute unmodified copies of the software to others without paying royalties or fees.
• Source Code Access: The complete source code of LibreOffice is publicly accessible, allowing users to study how the software works and audit it for security.

Modification and Distribution Rules

The “weak copyleft” nature of the MPL-2.0 introduces specific requirements when modifying the software:

• File-Level Copyleft: If you modify an existing file covered by the MPL-2.0 and distribute that binary or software, you must make the source code of those modifications available under the MPL-2.0.
• Larger Works: Unlike strict copyleft licenses like the GNU General Public License (GPL), the MPL-2.0 allows developers to combine MPL-licensed files with proprietary or differently licensed code to create a “Larger Work,” provided the MPL-covered files remain openly accessible under the MPL.
• Notice Preservation: Any distributed copies must retain all original copyright notices, trademarks, and license disclaimers.

Historical Context and Secondary Licenses

LibreOffice originated as a fork of OpenOffice.org, which originally used the GNU Lesser General Public License version 3 (LGPLv3). While modern code contributions are licensed under MPL-2.0, some legacy components remain dual-licensed or governed by the LGPLv3+ or Apache License 2.0 to ensure continuous backward compatibility and smooth development.