O'Reilly Media, thanks to Tim O'Reilly, have long been associated with leading edge thought and trends shaping the future. This includes being one of the first and foremost book publishers using Open licensing models such as Creative Commons. See their Open Books collection for good reference.
This is an online version of our open source book based on the version published by Morgan Kaufmann in April 2005. We post it online in the hopes that people will find it useful. Feel free to link to it.