The first subject, Information, is perhaps the oldest part of this movement. Gutenberg can be considered one of its earliest advocates, since he invented the printing press, allowing the public at large to read and become educated. Today, Open Information has grown phenomenally with the internet, which allows anybody online to access an immense wealth of knowledge.
More recently there have been more or less successful attempts to centralize open knowledge. Wikipedia, for example, is an online encyclopedia where anyone can contribute, correct, or complete articles. In April 2005 it had some 538,000 articles in English (and more than 940 articles added per day), making it larger than any other encyclopedia, printed or online.