[edit] History of Hypertext
- in the early 20th century, two visionaries attacked the cross-referencing problem through proposals based on labor-intensive brute force methods:
- Paul Otlet proposed a proto-hypertext concept based on his monographic principle in which all documents would be decomposed down to unique phrases stored on index cards.
- In the 1930s, H.G. Wells proposed the creation of a WorldBrain. For reasons of cost, neither proposal got very far.
- In 1945, Vannevar Bush published "As We May Think" In his article, Bush describes how the human mind works by associating related pieces of information. He applied this concept to a machine, called the Memex, which allowed the user to tie two relevant pieces of information, from two separate documents, together. This idea of association is credited as being the first attempt to describe hypertext.
- Engelbart's oN Line System (NLS/Augment). In 1963, Engelbart described a computer system that would augment man's intellect, by allowing the user to interact with the system using special cooperative devices. As a result the amount of information that a user could manipulate and understand would steadily increase, effectively amplifying the native intelligence of the user. The NLS system was implemented five years later at the Stanford Research Institute. It allowed users to create any number of links between elements within a document and between the documents themselves.
- Nelson's Xanadu System. During the development of the NLS, Ted Nelson was also developing his own ideas about augmentation. Nelson's system would only allow the storage of documents in their original format and any modifications made to these documents, e.g. a different paragraph etc. By using links between these modifications and the original documents, previous versions could be easily reconstructed. New links could easily be created between different bodies of text and therefore new pathways could be formed through the material. It was from this system of linking large bodies of text together that Ted Nelson created the term hypertext. Ted Nelson helped Andries van Dam develop the Hypertext Editing System in 1968 at Brown University; Ted Nelson and the Xanadu project
[edit] Definitions of Hypertext & Hypermedia
- Hypertext - Text which is not constrained to be linear.more...
- MultiMedia Hypertext . HyperMedia and HyperText tend to be used loosely in place of each other. Media other than text typically include graphics, sound, and video.
other definitions
and an illustration
[edit] Hypertext implementation
There are several standards for implementing hypertext.
Here are the most important ones:
- SGML -The Standard Generalized Markup Language (SGML) is a metalanguage in which one can define markup languages for documents. SGML provides a variety of markup syntaxes that can be used for many applications. SGML was originally designed to enable the sharing of machine-readable documents in large projects in government, legal and industry, which have to remain readable for several decades—a very long time in information technology. It has also been used extensively in the printing and publishing industries, but its complexity has prevented its widespread application for small-scale general-purpose use.
- HTML - short for Hypertext Markup Language, is the predominant markup language for web pages. It provides a means to describe the structure of text-based information in a document — by denoting certain text as headings, paragraphs, lists, and so on — and to supplement that text with interactive forms, embedded images, and other objects. HTML is written in the form of labels (known as tags), surrounded by angle brackets. HTML can also describe, to some degree, the appearance and semantics of a document, and can include embedded scripting language code which can affect the behavior of web browsers and other HTML processors.
- XML -The Extensible Markup Language (XML) is a general-purpose markup language. It is classified as an extensible language because it allows its users to define their own tags. Its primary purpose is to facilitate the sharing of structured data across different information systems, particularly via the Internet.[2] It is used both to encode documents and serialize data. It started as a simplified subset of the Standard Generalized Markup Language (SGML), and is designed to be relatively human-legible. By adding semantic constraints, application languages can be implemented in XML. These include XHTML, RSS, MathML, GraphML, Scalable Vector Graphics, MusicXML, and thousands of others. Moreover, XML is sometimes used as the specification language for such application languages. XML is recommended by the World Wide Web Consortium. It is a fee-free open standard.
- XHTML - The Extensible HyperText Markup Language, or XHTML, is a markup language that has the same depth of expression as HTML, but also conforms to XML syntax.
Whereas HTML is an application of Standard Generalized Markup Language (SGML), a very flexible markup language, XHTML is an application of XML, a more restrictive subset of SGML. Because they need to be well-formed, true XHTML documents allow for automated processing to be performed using standard XML tools—unlike HTML, which requires a relatively complex, lenient, and generally custom parser. XHTML can be thought of as the intersection of HTML and XML in many respects.
- Web standard:
- Structure - specified by XHTML,
- presentation by CSS, and
- behavior by DOM-based scripting(DOM-Document Object Model)
- Browsers:Netscape, Internet Explorer, Firefox, Safari, Mozilla, Chrome
[edit] MarkUp validators
[edit] Advanced Hypertext
- Fat Links
- Typed Links
- User-Constructed Structure
- Integrated search and browsing
[edit] Hypertext Applications