Since beta software has become the norm in these days of rapid innovation on the Internet, we realized that there was no reason we couldn't apply the same model to our high-priority books. By printing this beta edition we can get timely information out to our customers without giving the impression that the book is in its final form.
In order to get the beta version of the book out quickly (which is the whole point!) we have not put it through all the quality-control checks that O'Reilly books usually go through. So forgive us if you find typos or awkward prose. As a reader of this beta edition of the book, you can help us to improve the final edition by serving as a beta-tester. If you find errors, inaccuracies, or typos anywhere in the book, or explanations that are not clear, or statements that are misleading, please let us know about them by sending email to firstname.lastname@example.org.