GPL aims to protect the four freedoms of free software

The GPL (GNU General Public License) is a free software license that guarantees end users the freedom to run, study, share, and modify the software. Created by Richard Stallman for the GNU Project, it is a copyleft license, meaning that any derivative work must be distributed under the same or equivalent license terms. This ensures that the software and its derivatives remain free software.

"The GNU General Public License is designed to make sure that you have the freedom to distribute copies of free software (and charge for them if you wish)." - Richard Stallman

The GPL aims to protect the four freedoms of free software: the freedom to use the software for any purpose, the freedom to study how the software works, the freedom to redistribute copies, and the freedom to modify the software and distribute those modifications.

"Free software is a matter of liberty, not price. To understand the concept, you should think of 'free' as in 'free speech,' not as in 'free beer'." - Richard Stallman

The most commonly used version as of my last update is GPL version 3 (GPLv3), which addresses some modern computing issues such as software patents, TiVoization, and digital rights management.

"The Free Software Foundation recommends the GNU AGPL for any software which will commonly be run over a network." - Richard Stallman

GPLv3 strengthens the protection of users' freedom, ensuring that even in an evolving digital landscape, the principles of free software remain intact.

"The GNU General Public License is not only a copyright license, it is a copyleft license." - Richard Stallman

By requiring that derivative works also be licensed under the GPL, it fosters a collaborative environment where improvements and innovations are shared and accessible to all.

"The GPL was designed to give users the freedom to modify and redistribute free software." - Richard Stallman

One of the key aspects of the GPL is its emphasis on community and cooperation rather than strict control or proprietary interests.

"In the long term, the GPL will be seen as having contributed more to the success of free software than BSD-style licenses." - Richard Stallman

In essence, the GPL is a cornerstone of the free software movement, ensuring that software remains a tool for empowerment and innovation rather than a means of control.