Open Access Books & Resources

This tutorial is the culmination of nearly a decade of studying and writing about software freedom licensing and the GPL. Each part of this tutorial is a course unto itself, educating the reader on a myriad of topics from the deep details of the GPLv2 and GPLv3, common business models in the copyleft licensing area (both the friendly and unfriendly kind), best practices for compliance with the GPL, for engineers, managers, and lawyers, as well as real-world case studies of GPL enforcement matters.

It is unlikely that all the information herein is necessary to learn all at once, and therefore this tutorial likely serves best as a reference book. The material herein has been used as the basis for numerous live tutorials and discussion groups since 2002, and the materials have been periodically updated. They likely stand on their own as excellent reference material.

The copyright holders hereby grant the freedom to copy, modify, convey, Adapt, and/or redistribute this work under the terms of the Creative Commons Attribution Share Alike 4.0 International License. A copy of that license is available at https://creativecommons.org/licenses/by-sa/4.0/legalcode. Each part of this book, except the appendix, is separately under this same license, but copyrighted by different entities at different times. Each part therefore also contains its own copyright and licensing notice. The notice above is for the entire work, and includes the full copyright and licensing details, except for the appendix. Since the appendix includes copies of the texts of various licenses published by FSF, and they are all licensed under the license, “Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.”. However, those who seek to make modified versions of those licenses should note the explanation given in the GPL FAQ.