GPL-3 vs. LGPL-3

Attribute	GPL-3	LGPL-3
License Type	General Public License	Lesser General Public License
Compatibility with other licenses	Compatible with GPL-3	Compatible with GPL-3
Derivative Works	Derivative works must also be licensed under GPL-3	Derivative works can be licensed under any license
Dynamic Linking	Not allowed	Allowed
Static Linking	Not allowed	Allowed

Introduction

When it comes to open-source licenses, two of the most popular choices are the GNU General Public License version 3 (GPL-3) and the GNU Lesser General Public License version 3 (LGPL-3). Both licenses are created by the Free Software Foundation and are designed to protect the rights of users and developers of open-source software. While they share some similarities, there are also key differences between GPL-3 and LGPL-3 that developers should be aware of when choosing a license for their projects.

Scope of Application

One of the main differences between GPL-3 and LGPL-3 is the scope of application. GPL-3 is a strong copyleft license, which means that any derivative works of a GPL-3 licensed software must also be licensed under the GPL-3. This ensures that the source code of the software remains open and freely available to all users. On the other hand, LGPL-3 is a weaker copyleft license that allows developers to link their proprietary software with LGPL-3 licensed libraries without having to release the source code of their proprietary software.

Compatibility

Another important factor to consider when choosing between GPL-3 and LGPL-3 is compatibility with other licenses. GPL-3 is not compatible with many proprietary licenses, as it requires that any derivative works be licensed under the GPL-3 as well. This can be a barrier for developers who want to use GPL-3 licensed software in conjunction with proprietary software. On the other hand, LGPL-3 is more permissive and allows developers to use LGPL-3 licensed libraries in proprietary software without having to release the source code of the proprietary software.

Dynamic Linking

One of the key differences between GPL-3 and LGPL-3 is how they handle dynamic linking. Dynamic linking is a method of linking software libraries at runtime, rather than at compile time. GPL-3 considers dynamic linking to be a form of distribution, which means that any software that dynamically links to a GPL-3 library must also be licensed under the GPL-3. This can be a limitation for developers who want to use GPL-3 licensed libraries in proprietary software. On the other hand, LGPL-3 allows for dynamic linking with proprietary software, making it a more flexible choice for developers.

Code Modifications

When it comes to making modifications to the code, GPL-3 and LGPL-3 have different requirements. GPL-3 requires that any modifications to the code be released under the GPL-3, ensuring that the source code remains open and freely available. This can be a benefit for the open-source community, as it encourages collaboration and sharing of code. On the other hand, LGPL-3 only requires that modifications to the library itself be released under the LGPL-3, allowing developers to make modifications to the code without having to release the source code of their entire project.

Conclusion

In conclusion, both GPL-3 and LGPL-3 are popular choices for open-source licenses, each with its own set of advantages and limitations. GPL-3 is a strong copyleft license that ensures the source code of the software remains open and freely available, while LGPL-3 is a weaker copyleft license that allows for more flexibility in how developers can use and distribute the software. When choosing between GPL-3 and LGPL-3, developers should consider factors such as the scope of application, compatibility with other licenses, dynamic linking, and code modifications to determine which license best suits their project's needs.