Apache License Version 2.0

While I was finishing the final edits for this book, the board of directors of the Apache Software Foundation approved version 2.0 of the Apache License. I debated with myself whether to insert a review of that license here. I was reminded of a cat chasing its tail. If I delay the publication of this book for every new license that comes along, I'll never finish.

The Apache License version 2.0 is a much more robust open source license than the other academic licenses already discussed in this chapter. It deserves careful analysis, perhaps a chapter all its own like the GPL, MPL, CPL, and OSL/AFL licenses in the chapters that follow this one. It is a very good open source license, a dramatic improvement over its predecessor. I decided that, rather than try to catch that Apache License for this book, I will use it only as an object lesson: Open source licensing is part of a dynamic, fast-moving world. New licenses and licensing strategies are introduced constantly. Companies that intend to play seriously in the open source marketplace will want to dedicate some effort to remaining current. This book unfortunately doesn't have all the answers.