1. The Cathedral and the Bazaar by Eric S Raymond
And the manifesto begat the book.
Two years after his manifesto, The Cathedral and the Bazaar, caused a stir in the IT community, Eric Raymond gathered together his thoughts on open software development in a book of the same title. Eleven years later, we can see how so much of the philosophy outlined in the book has created a new paradigm for computing. Possibly the most influential computer book of them all.
The Cathedral & the Bazaar by Eric S Raymond, 1999, O'Reilly, ISBN 1-56597249