AGPL

The Affero General Public License (AGPL) is a free software license published by the Free Software Foundation. It is a strong copyleft license designed to close the server-proxy loophole of the GPL by requiring that the complete corresponding source code of modified versions be made available to users who interact with the software over a network.

A key feature of the AGPL is the obligation to provide access to source code not only when distributing software, but also when the software is used to provide a service over a network. If you modify AGPL-licensed software and deploy it to run as part of a network service, you must offer the corresponding source code to all users who interact with the program remotely, under the same AGPLv3 terms. The license defines corresponding source as the source code needed to enable the user to modify and run the work, including any scripts used to control compilation and installation.

By design, the AGPL aims to ensure that improvements to software used over a network remain freely available. It is a free software license, granting users the rights to run, study, modify, and distribute the software, provided they comply with the license terms.

Scope and adoption: AGPLv3, released in its current form in 2007, is the latest version. It is a variant of the GPL family that adds the network interaction clause and is considered more restrictive than GPLv3 for server-based deployments. It is chosen by some projects to prevent the withholding of improvements in cloud or SaaS offerings, though it is not as widely adopted as GPLv3 for traditional software distribution.