Serendipity35

In 2002, computer scientist and physicist Stephen Wolfram published a bestselling book A New Kind of Science about fundamental problems in science, from the origins of apparent randomness in physical systems, to the development of complexity in biology, the ultimate scope and limitations of mathematics, the possibility of a truly fundamental theory of physics, the interplay between free will and determinism, and the character of intelligence in the universe.
Wolfram’s blog post announced this online edition, he revisits the intellectual contributions he made with the book.
You can still buy the book, but now Wolfram has put his book online in its entirety. You can read it online for free and download it as PDFs.
The book is also part of a very good collection of free eBooks for iPad, Kindle & Other Devices from openculture.com