I was extremely impressed by the large number of key players in the Free Software revolution that O'Reilly brought together for this book.
Not only can newcomers use the text to better understand Free Software but even relative veterans are provided with food for thought particularly in relation to development processes and how to make a commercial success of Free Software.
It also provides some interesting insights into why software like Apache, Perl and GNU/Linux are designed the way they are - from their creators' own words.
The two reasons it gets only 4 stars are: a) Silly spelling errors e.g. "weather" when it should have been "whether" b) A major bias towards the Open Source terminology instead of Free Software though they do fairly discuss why this is done (not that I totally agree with them).
A useful and interesting book that may well become the key record of what happened in the past 20 years to culminate in proprietry software becoming so uncool.