The Founding Document...

...of the World Wide Web.  This is the full text, with accompanying diagrams, of Tim Berners-Lee's original proposal to CERN, in March 1989.  This proposal led directly to the development of HTTP servers and web browsers, which in turn (because they were so intuitive and easy for mere mortals to use) ushered in the Internet world we live in today.  A fascinating read for anyone interested in the history of technology...