Which Open Source License Does Audacity Use?

Audacity is distributed to the public under the GNU General Public License, Version 3 (GPLv3). This article explains the terms of Audacity's licensing, its transition from earlier GPL versions, and what the GPLv3 license means for end users, developers, and distributors.

The Current License: GNU GPLv3

Audacity is currently released under the GNU General Public License, Version 3 (GPLv3). The GPLv3 is a copyleft, free software license published by the Free Software Foundation (FSF). It guarantees end users the freedom to run, study, share, and modify the software without paying licensing fees.

Historical Context and Transition

For most of its history, Audacity was distributed under the GNU General Public License, Version 2 (GPLv2 or "GPLv2 or later"). Following the acquisition of the Audacity project by the Muse Group in 2021, the development team updated the license to GPLv3 starting with Audacity version 3.1.3.

This transition required establishing a Contributor License Agreement (CLA) to ensure all contributed code could legally be relicensed under the updated terms of GPLv3.

Key Terms of the GPLv3 for Audacity

Under the GPLv3, users and developers are granted specific rights and responsibilities:

• Freedom to Use: You can download, install, and use Audacity for any purpose, including commercial, personal, educational, or governmental projects, completely free of charge.
• Access to Source Code: The complete source code for Audacity must be made available to anyone who receives the software.
• Right to Modify: You can change, adapt, and build upon the original source code to create custom versions or fork the software.
• Copyleft Requirement: If you distribute modified versions of Audacity, those modifications must also be released under the GPLv3 license. You cannot make the software proprietary or close off the source code.
• Hardware Restrictions and Patent Rights: GPLv3 includes explicit protections preventing "tivoization" (using hardware restrictions to prevent modified software from running) and provides explicit patent grants to protect users from patent infringement claims by contributors.

Third-Party Libraries

While Audacity as an application is distributed under the GPLv3, it incorporates several third-party libraries and dependencies. These components are licensed under compatible open-source licenses, such as the GNU Lesser General Public License (LGPL), the BSD License, and the MIT License. When compiled into the final application distributed to users, the entire bundle complies with the requirements of GPLv3.