When it comes to open source software licenses, the General Public License (GPL) has become one of the most popular choices among developers and companies alike. It allows for the distribution and modification of software while ensuring that the source code remains open and freely accessible. However, there are two versions of the GPL - v2 and v3 - and understanding the differences between them is crucial for anyone looking to use or create open source software.
The GPL v2, also known as the GNU General Public License version 2, was first released in 1991 by the Free Software Foundation (FSF). It was the first major update to the original GPL, which was created in 1989. This version is still widely used today and is the preferred license for many projects, including the Linux kernel.
One of the key differences between GPL v2 and v3 is the inclusion of the Affero clause in v3. This clause requires that if a modified version of the software is used to provide a service over a network, the source code of that modified version must be made available to users of the service. This was added to ensure that companies cannot take advantage of open source software without contributing back to the community.
Another significant difference between the two versions is the patent clause in v3. This clause states that if a patent holder sues someone for patent infringement relating to the software distributed under the GPL v3, they lose the right to distribute the software under the same license. This was added to prevent companies from using patents to restrict the use and distribution of open source software.
In terms of compatibility, the GPL v2 is compatible with versions 2 and 3 of the GNU Lesser General Public License (LGPL), while the GPL v3 is only compatible with version 3 of the LGPL. This means that code licensed under the GPL v2 can be combined with code licensed under the LGPL v2 or v3, but code licensed under the GPL v3 can only be combined with code licensed under the LGPL v3.
Another important difference to note is the inclusion of a “cure” provision in the GPL v3. This provision gives violators of the license a period of time to fix any non-compliant behavior before their license is terminated. This was added to give companies and individuals a chance to rectify any unintentional violations before facing legal consequences.
Lastly, the GPL v3 also includes additional language around digital rights management (DRM). It prohibits the use of DRM to restrict users’ rights to modify and distribute the software. This was added to protect the freedom of users and prevent companies from using DRM to control and profit from open source software.
In conclusion, while the GPL v2 and v3 have similar goals of promoting open source software, they differ in their approach and provisions. The GPL v3 addresses some of the shortcomings of the GPL v2 and provides more protection for open source software. However, both licenses have their strengths and weaknesses, and the choice between them ultimately depends on the needs and preferences of the developer or company. Whichever license is chosen, it is important to understand and comply with its terms to ensure the continued growth and success of the open source community.
