1960 жылы құрылған алғашқы гипермәтін жобасы

First hypertext project, founded in 1960

Project Xanadu ('/z//æ//n//ə//d//uː/ ZANədoo) was the first hypertext project, founded in 1960 by Ted Nelson. Administrators of Project Xanadu have declared it superior to the World Wide Web, with the mission statement: "Today's popular software simulates paper. The World Wide Web (another imitation of paper) trivialises our original hypertext model with one way ever breaking links and no management of version or contents." Wired magazine published an article entitled "The Curse of Xanadu", calling Project Xanadu "the longest running vaporware story in the history of the computer industry". The first attempt at implementation began in 1960, but it was not until 1998 that an incomplete implementation was released. A version described as "a working deliverable", OpenXanadu, was made available in 2014.

Nelson's vision was for a "digital repository scheme for world wide electronic publishing". Nelson states that the idea began in 1960, when he was a student at Harvard University. He proposed a machine language program which would store and display documents, together with the ability to perform edits. This was different from a word processor (which had not been invented yet) in that the functionality would have included visual comparisons of different versions of the document, a concept Nelson would later call "intercomparison". On top of this basic idea, Nelson wanted to facilitate nonsequential writing, in which the reader could choose their own path through an electronic document. He built upon this idea in a paper to the Association for Computing Machinery (ACM) in 1965, calling the new idea "zippered lists". These zippered lists would allow compound documents to be formed from pieces of other documents, a concept named transclusion. ), hired many of the Xanadu programmers (including lead architects Mark S. Miller, Dean Tribble and Ravi Pandya)

In 1998, Nelson released the source code to Xanadu as Project Udanax, in the hope that the techniques and algorithms used could help to overturn some software patents.

In 2007, Project Xanadu released XanaduSpace 1.0.

A version described as "a working deliverable", OpenXanadu, was made available on the World Wide Web in 2014. It is called open because "you can see all the parts", but as of 2014 the site stated that it was "not yet open source". On the site, the creators claim that Tim Berners Lee stole their idea, and that the World Wide Web is a "bizarre structure created by arbitrary initiatives of varied people and it has a terrible programming language" and that Web security is a "complex maze". They go on to say that Hypertext is designed to be paper, and that the World Wide Web allows nothing more than dead links to other dead pages. In 2016, Ted Nelson was interviewed by Werner Herzog in his documentary, Lo and Behold, Reveries of the Connected World. "By some, he was labeled insane for clinging on," Herzog said. "To us, you appear to be the only one who is clinically sane." Nelson was delighted by the praise. "No one has ever said that before!" said Nelson. "Usually I hear the opposite."

Every Xanadu server is uniquely and securely identified. Every Xanadu server can be operated independently or in a network. Every user is uniquely and securely identified. Every user can search, retrieve, create and store documents. Every document can consist of any number of parts each of which may be of any data type. Every document can contain links of any type including virtual copies ("transclusions") to any other document in the system accessible to its owner. Links are visible and can be followed from all endpoints. Permission to link to a document is explicitly granted by the act of publication. Every document can contain a royalty mechanism at any desired degree of granularity to ensure payment on any portion accessed, including virtual copies ("transclusions") of all or part of the document. Every document is uniquely and securely identified. Every document can have secure access controls. Every document can be rapidly searched, stored and retrieved without user knowledge of where it is physically stored. Every document is automatically moved to physical storage appropriate to its frequency of access from any given location. Every document is automatically stored redundantly to maintain availability even in case of a disaster. Every Xanadu service provider can charge their users at any rate they choose for the storage, retrieval and publishing of documents. Every transaction is secure and auditable only by the parties to that transaction. The Xanadu client–server communication protocol is an openly published standard. Third party software development and integration is encouraged.

In the design of the Xanadu computer system, a tumbler is an address of any range of content or link or a set of ranges or links. According to Gary Wolf in Wired, the idea of tumblers was that "the address would not only point the reader to the correct machine, it would also indicate the author of the document, the version of the document, the correct span of bytes, and the links associated with these bytes." Tumblers were created by Roger Gregory and Mark Miller. The idea behind tumblers comes from transfinite numbers.