Littera Deusto

Modern Languages, Basque Studies and Humanities

← →

Markup languages

octubre 21st, 2009 · No hay Comentarios

A markup language is a system for annotating a text in a way which is syntactically distinguishable from that text.The first language to make a clear and clean distinction between structure and presentation was Scribe, developed by Brian Reid. Scribe was revolutionary in a number of ways, not least that it introduced the idea of styles separated from the marked up document, and of a grammar controlling the usage of descriptive elements. Scribe influenced the development of Generalized Markup Language (later SGML) and is a direct ancestor to HTML and LaTeX.

However, IBM researcher Charles Goldfarb is more commonly seen today as the “father” of markup languages. Goldfarb hit upon the basic idea while working on a primitive document management system intended for law firms in 1969, and helped invent IBM GML later that same year. GML was first publicly disclosed in 1973.

Presentation Semantics  specify how a piece of formal language is represented in a way that is accesible and easy to human vision. Some of the markup languages contain this type of presentation (HTLM) but there are other which do not contain it (XML).

Presentation Semantics  and Style Sheets are related in a way that the last ones describe the semantics presentation of a document in Markup Language. Its principal application is in some HTML or XHTML web pages. These sheets enable to distingish the content from  presentation. Style sheets describe how documents are presented on screens, in print, or perhaps how they are pronounced. W3C has actively promoted the use of style sheets on the Web since the Consortium was founded in 1994.

Here we have a resumed list of the main markup languages and a little explanation:

TeX

TeX concentrated on detailed layout of text and font descriptions in order to typeset mathematical books in professional quality. This required Knuth to spend considerable time investigating the art of typesetting. However, TeX has a steep learning curve, so that it is mainly used in academia, where it is the de facto standard in many scientific disciplines. A TeX macro package known as LaTeX provides a descriptive markup system on top of TeX, and is widely used.

HTML and XML

Some markup languages, like HTML have presentation semantics, meaning their specification prescribes how the structured data is to be presented, but other markup languages, like XML, have no predefined semantics.

In XML we can distinguish three different types:

XHTML

(Extensible HyperText Markup Language) The language specification requires that XHTML Web documents must be well-formed XML documents – this allows for more rigorous and robust documents while using tags familiar from HTML.

TEI

The Text Encoding Initiative (TEI) is a consortium which collectively develops and maintains a standard for the representation of texts in digital form. Its chief deliverable is a set of Guidelines which specify encoding methods for machine-readable texts, chiefly in the humanities, social sciences and linguistics. It is used in two projects of the University of Deusto.

RDF/RSS

An RSS document (which is called a “feed”, “web feed”, or “channel”) includes full or summarized text, plus metadata such as publishing dates and authorship. Web feeds benefit publishers by letting them syndicate content automatically. They benefit readers who want to subscribe to timely updates from favored websites or to aggregate feeds from many sites into one place. RSS feeds can be read using software called an “RSS reader”, “feed reader”, or “aggregator”, which can be web-based, desktop-based, or mobile-device-based. A standardized XML file format allows the information to be published once and viewed by many different programs.

SOURCES:

Etiquetas:

  • Etiquetas