This is a book of essays on open source development. The first Open Sources was published in 1999, and most of the essays covered what open source is. This book examines what has happened in the open source community since that time. The essays are about many aspects of open source development, but the book can largely be divided into two sections. The first sections covers the business perspective. The essays in this section discuss the use of open source software in business, businesses based around open source software, and some of the pragmatics of open source development. The second section covers the cultural perspective on open source. It includes essays about how ideas from open source development have influenced other fields such as biology and knowledge sharing. Overall, the essays were insightful and interesting; some were particularly good, and others bored me nearly to tears. The book is worth reading if you are interested in open source. (Be warned though, the proof readers did not do the best job with this book.)