If you've held back from developing open source or free software projects because you don't understand the implications of the various licenses, you're not alone. Many developers believe in releasing their software freely, but have hesitated to do so because they're concerned about losing control over their software. Licensing issues are complicated, and both the facts and fallacies you hear word-of-mouth can add to the confusion.

Understanding Open Source and Free Software Licensing helps you make sense of the different options available to you. This concise guide focuses on annotated licenses, offering an in-depth explanation of how they compare and interoperate, and how license choices affect project possibilities. Written in clear language that you don't have to be a lawyer to understand, the book answers such questions as: What rights am I giving up? How will my use of OS/FS licensing affect future users or future developers? Does a particular use of this software--such as combining it with proprietary software--leave me vulnerable to lawsuits?

Following a quick look at copyright law, contracts, and the definition of "open source," the book tackles the spectrum of licensing, including:

The MIT (or X), BSD, Apache and Academic Free licenses

The GPL, LGPL, and Mozilla licenses

The QT, Artistic, and Creative Commons licenses

Classic Proprietary licenses

Sun Community Source license and Microsoft Shared Source project

The book wraps up with a look at the legal effects--both positive and negative--of open source/free software licensing.

Licensing is a major part of what open source and free software are all about, but it's still one of the most complicated areas of law. Even the very simple licenses are tricky. Understanding Open Source and Free Software Licensing bridges the gap between the open source vision and the practical implications of its legal underpinnings. If open source and free software licenses interest you, this book will help you understand them. If you're an open source/free software developer, this book is an absolute necessity.

Andrew M. St. Laurent is an experienced lawyer with a long-time interest in intellectual property, particularly software licensing.