You can purchase it at Amazon, Addison-Wesley, or in any number of places online or in the real world.
A few errors crept in, but so far only a few! Here's a list of errata.
In the spirit of our past work, our commitment to science and research, and our desire to help others we have also decided to put the text of the book online for free. Addison-Wesley was also kind enough to permit us to put up our final HTML drafts that we sent to the publisher; minus the final formatting and a few minor changes these should be very close to the book version and is suitable for printing, grep'ing, and the like. We will put up the final PDF version in the future as well.
We hope you find this useful; in addition to current owners all of this might be useful for those who cannot afford the printed version, would like to check it out without taking the fiscal plunge, or are just cheap ;-)
We ask that you honor the authors' request and please do not resell, redistribute this work via any physical media (CDs, DVDs, and the like) or place it on other web sites. The copyright is still retained by Pearson Education, Inc.
We'd like to encourage people to still purchase the work if you think it of value, and send a signal to other publishers that freedom of information doesn't necessarily mean that you cannot make an honest buck from your efforts. We'd also like to again thank Addison-Wesley for their commitment to education and knowledge and allowing us to do this.
And, for those who simply want the entire book in HTML form, here it is, zip'd (415 kB)
You can find complete copies of the programs that appear in the book, as well as the software we used in our measurements here: tar archive (375 kB) | PGP signature | README file (Wietse's PGP public key is here).
It was an enormous effort to finish the work - despite its small size - and we do hope you enjoy it. Feel free to send us email at firstname.lastname@example.org and email@example.com with commentary or critique.
Wietse & Dan