Understanding Open Source and Free Software Licensing

Preface

Free and open source development models have made tremendous contributions to computing, sustaining both research and commercial projects and making it easier for large groups of people, who may not even be acquainted, to help each other. While this growing activity has a promising future, all of this work is built on top of licenses—legal documents—that often seem arcane or difficult to understand. Businesses and individuals aren't always sure what is at stake in their decisions to participate, and deciding which license to use for a particular project can be a project of its own.

This book is designed to simplify those decisions, explaining the different licenses and their effects on projects, including both commercial and non-commercial projects. It explores how licenses can be used as glue to bind groups of people together in common, and how the different styles of license interact with different kinds of projects.

The licenses and projects covered include:

• MIT

• BSD

• Apache, Versions 1.0 and 2.0

• Academic Free License (AFL)

• GNU General Public License (GPL)

• GNU Lesser General Public License (LGPL)

• Mozilla Public License (MPL)

• Qt License

• Artistic License

• Creative Commons Licenses

• Sun Community Source License and Commercial Use Supplement

• Microsoft Shared Source Initiative

Each license is examined clause by clause, including both the original license text and explanation. This book also looks at issues affecting all of these licenses, including the formation of a contract, enforceability of warranty and other disclaimers, and cross-licensing.

Audience

A few lawyers will undoubtedly read this book, and hopefully find it useful, but you don't need to be a lawyer to read this book. Whether you're a programmer deciding what license to use in publishing a personal code library, a manager deciding if and how you can use open source code in your business, or a lawyer evaluating rules for integrating open source code with proprietary code, you should find the information you need here.