Hypertext Markup Language (HTML) is the standard markup language for creating web pages and web applications. With Cascading Style Sheets (CSS) and JavaScript, it forms a triad of cornerstone technologies for the World Wide Web.
In computer text processing, a markup language is a system for annotating a document in a way that is syntactically distinguishable from the text. The idea and terminology evolved from the "marking up" of paper manuscripts, i.e., the revision instructions by editors, traditionally written with a blue pencil on authors' manuscripts. In digital media, this "blue pencil instruction text" was replaced by tags, which indicate what the parts of the document are, rather than details of how they might be shown on some display. This lets authors avoid formatting every instance of the same kind of thing redundantly. It also avoids the pointlessness of specifying fonts and dimensions, which do not even apply to many users.
The Standard Generalized Markup Language is a standard for defining generalized markup languages for documents. ISO 8879 Annex A.1 defines generalized markup:-
Generalized markup is based on two postulates:
VoiceXML (VXML) is a digital document standard for specifying interactive media and voice dialogs between humans and computers. It is used for developing audio and voice response applications, such as banking systems and automated customer service portals. VoiceXML applications are developed and deployed in a manner analogous to how a web browser interprets and visually renders the Hypertext Markup Language (HTML) it receives from a web server. VoiceXML documents are interpreted by a voice browser and in common deployment architectures, users interact with voice browsers via the public switched telephone network (PSTN).
In web page design, and generally for all markup languages such as SGML, HTML, and XML, a well-formed element is one that is either a) opened and subsequently closed, or b) an empty element, which in that case must be terminated; and in either case which is properly nested so that it does not overlap with other elements.
In web development, "tag soup" is a pejorative term that refers to syntactically or structurally incorrect HTML written for a web page. Because web browsers have historically treated HTML syntax or structural errors leniently, there has been little pressure for web developers to follow published standards, and therefore there is a need for all browser implementations to provide mechanisms to cope with the appearance of "tag soup", accepting and correcting for invalid syntax and structure where possible.
A numeric character reference (NCR) is a common markup construct used in SGML and SGML-derived markup languages such as HTML and XML. It consists of a short sequence of characters that, in turn, represents a single character. Since WebSgml, XML and HTML 4, the code points of the Universal Character Set (UCS) of Unicode are used. NCRs are typically used in order to represent characters that are not directly encodable in a particular document. When the document is interpreted by a markup-aware reader, each NCR is treated as if it were the character it represents.
The following tables compare general and technical information for a number of document markup languages. Please see the individual markup languages' articles for further information.
STEP-XML is a short term for ISO 10303-28, Industrial automation systems and integration—Product data representation and exchange—Part 28: Implementation methods: XML representations of EXPRESS schema and data. STEP-XML specifies the use of the Extensible Markup Language (XML) to represent EXPRESS schema and the data that is governed by those EXPRESS schema. It is an alternative method to STEP-File for the exchange of data according to ISO 10303.
Speech Synthesis Markup Language (SSML) is an XML-based markup language for speech synthesis applications. It is a recommendation of the W3C's voice browser working group. SSML is often embedded in VoiceXML scripts to drive interactive telephony systems. However, it also may be used alone, such as for creating audio books. For desktop applications, other markup languages are popular, including Apple's embedded speech commands, and Microsoft's SAPI Text to speech (TTS) markup, also an XML language.
Open Scripture Information Standard (OSIS) is an XML application, that defines tags for marking up Bibles, theological commentaries, and other related literature.
Office Open XML is a zipped, XML-based file format developed by Microsoft for representing spreadsheets, charts, presentations and word processing documents. The format was initially standardized by Ecma, and by the ISO and IEC in later versions.
C. Michael Sperberg-McQueen is an American markup language specialist. He was co-editor of the Extensible Markup Language (XML) 1.0 spec (1998), and chair of the XML Schema working group.
MECS is the Multi-Element Code System, a markup system developed by the Wittgenstein Archives at the University of Bergen. It is very similar to SGML and XML except that it allows elements to overlap.
A well-formed document in XML is a document that "adheres to the syntax rules specified by the XML 1.0 specification in that it must satisfy both physical and logical structures".
