HTML5 is the next major revision of
HTMLHTML, which stands for Hyper Text Markup Language, is the predominant markup language for web pages. It provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists etc as well as for links, quotes, and other items. It allows images...
(Hypertext Markup Language), the core
markup languageA markup language is a system for annotating a text in a way which is syntactically distinguishable from that text. Examples include revision instructions by editors, traditionally written with a blue pencil on authors' manuscripts, typesetting instructions such those found in troff and LaTeX, and...
of the
World Wide WebThe World Wide Web is a system of interlinked hypertext documents accessed via the Internet. With a web browser, one can view Web pages that may contain text, images, videos, and other multimedia and navigate between them using hyperlinks...
. The
Web Hypertext Application Technology Working GroupThe Web Hypertext Application Technology Working Group, or WHATWG, is a community of people interested in evolving HTML and related technologies. The WHATWG was founded by individuals from Apple, the Mozilla Foundation and Opera Software. Since then, the editor of the WHATWG specifications, Ian...
(WHATWG) started work on the specification in June 2004 under the name Web Applications 1.0.
HTML5 is the proposed next standard for HTML 4.01, XHTML 1.0 and DOM Level 2 HTML. HTML5 is expected to be a game-changer in Web application development, making obsolete such plug-in-based
rich Internet applicationRich Internet applications are web applications that have most of the characteristics of desktop applications, typically delivered by way of standards based web browser plug-ins or independently via sandboxes or virtual machines...
(RIA) technologies as
Adobe FlashAdobe Flash is a multimedia platform originally acquired by Macromedia and currently developed and distributed by Adobe Systems. Since its introduction in 1996, Flash has become a popular method for adding animation and interactivity to web pages...
,
Microsoft SilverlightMicrosoft Silverlight is a web application framework, integrating multimedia, graphics, animations and interactivity into a single runtime environment. Initially released as a video streaming plugin, later versions brought additional interactivity features and support for .NET languages and...
, and Sun
JavaFXJavaFX is a software platform for creating and delivering rich Internet applications that can run across a wide variety of connected devices. The current release enables building applications for desktop, browser and mobile phones...
.
The ideas behind HTML5, originally referred to as
Web Applications 1.0, were pioneered in 2004 by the WHATWG; HTML5 incorporates
Web Forms 2.0, another WHATWG specification.
The HTML5 specification was adopted as the starting point of the work of the new HTML working group of the W3C in 2007.
The working group published the First Public Working Draft of the specification on January 22, 2008.
HTML5 is the next major revision of
HTMLHTML, which stands for Hyper Text Markup Language, is the predominant markup language for web pages. It provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists etc as well as for links, quotes, and other items. It allows images...
(Hypertext Markup Language), the core
markup languageA markup language is a system for annotating a text in a way which is syntactically distinguishable from that text. Examples include revision instructions by editors, traditionally written with a blue pencil on authors' manuscripts, typesetting instructions such those found in troff and LaTeX, and...
of the
World Wide WebThe World Wide Web is a system of interlinked hypertext documents accessed via the Internet. With a web browser, one can view Web pages that may contain text, images, videos, and other multimedia and navigate between them using hyperlinks...
. The
Web Hypertext Application Technology Working GroupThe Web Hypertext Application Technology Working Group, or WHATWG, is a community of people interested in evolving HTML and related technologies. The WHATWG was founded by individuals from Apple, the Mozilla Foundation and Opera Software. Since then, the editor of the WHATWG specifications, Ian...
(WHATWG) started work on the specification in June 2004 under the name Web Applications 1.0.
HTML5 is the proposed next standard for HTML 4.01, XHTML 1.0 and DOM Level 2 HTML. HTML5 is expected to be a game-changer in Web application development, making obsolete such plug-in-based
rich Internet applicationRich Internet applications are web applications that have most of the characteristics of desktop applications, typically delivered by way of standards based web browser plug-ins or independently via sandboxes or virtual machines...
(RIA) technologies as
Adobe FlashAdobe Flash is a multimedia platform originally acquired by Macromedia and currently developed and distributed by Adobe Systems. Since its introduction in 1996, Flash has become a popular method for adding animation and interactivity to web pages...
,
Microsoft SilverlightMicrosoft Silverlight is a web application framework, integrating multimedia, graphics, animations and interactivity into a single runtime environment. Initially released as a video streaming plugin, later versions brought additional interactivity features and support for .NET languages and...
, and Sun
JavaFXJavaFX is a software platform for creating and delivering rich Internet applications that can run across a wide variety of connected devices. The current release enables building applications for desktop, browser and mobile phones...
.
The ideas behind HTML5, originally referred to as
Web Applications 1.0, were pioneered in 2004 by the WHATWG; HTML5 incorporates
Web Forms 2.0, another WHATWG specification.
The HTML5 specification was adopted as the starting point of the work of the new HTML working group of the W3C in 2007.
The working group published the First Public Working Draft of the specification on January 22, 2008. The specification is an ongoing work, and is expected to remain so for many years, although parts of HTML5 are going to be finished and implemented in browsers before the whole specification reaches final Recommendation status. The editors are
Ian HicksonIan 'Hixie' Hickson is the author and maintainer of the Acid2 and Acid3 tests, and the Web Applications 1.0/HTML 5 specification.[, Sean Michael Kerner, internetnews.com, January 25, 2008] He is known as a proponent of web standards, and has played a crucial role in...
of Google, Inc. and
David HyattDave Hyatt is an American software developer currently employed by Apple Inc. , where he is part of the development team responsible for the Safari web browser and WebKit framework. Hyatt was part of the original team that shipped the beta releases and 1.0 release of Safari...
of Apple, Inc.
New markup
HTML5 provides a number of new
elementsIn an HTML document, HTML elements are tags, as well as text, which act as indicators to a web browser as to how the document is to be interpreted by the browser and ultimately presented on the user's computer screen....
and attributes that reflect typical usage on modern Web sites. Some of them are
semanticThe Semantic Web is an evolving development of the World Wide Web in which the meaning of information and services on the web is defined, making it possible for the web to understand and satisfy the requests of people and machines to use the web content...
replacements for common uses of generic block and inline elements, for example (website navigation block) and . Other elements provide new functionality through a standardized interface, such as the and elements.
Some deprecated elements from HTML 4.01 have been dropped, including purely presentational elements such as and , whose effects are achieved using
CSSCascading Style Sheets is a style sheet language used to describe the presentation semantics of a document written in a markup language...
. There is also a renewed emphasis on the importance of
DOM scriptingThe term DOM scripting refers to programmatically accessing the Document Object Model . In common usage, DOM scripting implies JavaScript. DOM scripting has its roots in Dynamic HTML , but is more structured...
in Web behavior.
The HTML5 syntax is no longer based on SGML despite its markup being very close. It has, however, been designed to be backward compatible with common parsing of older versions of HTML. It comes with a new introductory line which looks like an SGML document type declaration, , which enables standards-compliant rendering in all browsers that use "DOCTYPE sniffing".
New APIs
In addition to specifying markup, HTML5 specifies scripting application programming interfaces (APIs). Existing
document object modelThe Document Object Model is a cross-platform and language-independent convention for representing and interacting with objects in HTML, XHTML and XML documents. Aspects of the DOM may be addressed and manipulated within the syntax of the programming language in use...
(DOM) interfaces are extended and
de factoDe facto is a Latin expression that means "by [the] fact". In law, it is meant to mean "in practice but not necessarily ordained by law" or "in practice or actuality, but without being officially established"...
features documented. There are also new APIs, such as:
- The canvas tag
The canvas element is part of HTML 5 and allows for dynamic scriptable rendering of bitmap images.It was initially introduced by Apple for use inside their own Mac OS X WebKit component, powering applications like Dashboard widgets and the Safari browser...
for immediate modeImmediate mode rendering is a style for application programming interfaces of graphics libraries, in which client calls directly cause rendering of graphics objects to the display. Every frame, the application must redraw everything regardless of actual changes...
2D drawing
- Timed media playback
- Offline storage database
DOM storage is a mechanism for web applications to store data in a web browser. DOM storage supports persistent data storage, similar to cookies, as well as window-local storage....
- Document editing
- Drag-and-drop
In computer graphical user interfaces, drag-and-drop is the action of clicking on a virtual object and dragging it to a different location or onto another virtual object...
- Cross-document messaging
- Browser history management
- MIME type and protocol handler registration
Some of the new features are part of HTML5 mainly because there are no volunteers to split HTML5 and maintain separate specifications of these features.
Differences from HTML 4.01/XHTML 1.x
The following is a cursory list of differences and some specific examples.
- New parsing rules oriented towards flexible parsing and compatibility; not based on SGML
- Ability to use inline SVG and MathML
Mathematical Markup Language is an application of XML for describing mathematical notations and capturing both its structure and content. It aims at integrating mathematical formulae into World Wide Web documents...
in text/html
- New elements
In an HTML document, HTML elements are tags, as well as text, which act as indicators to a web browser as to how the document is to be interpreted by the browser and ultimately presented on the user's computer screen....
– section, article, footer, audio, video, progress, nav, meter, time, aside, canvasThe canvas element is part of HTML 5 and allows for dynamic scriptable rendering of bitmap images.It was initially introduced by Apple for use inside their own Mac OS X WebKit component, powering applications like Dashboard widgets and the Safari browser...
- New types of form controls – dates and times,
email, url, search
- New attributes –
ping (on a and area), charset (on meta), async (on script)
- Global attributes (that can be applied for every element) –
id, tabindex, hidden, data-* (custom data attributes)
- Deprecated elements dropped –
center, font, strike, framesetOn a web page, framing means that a website can be organized into frames. Each frame displays a different HTML document. Headers and sidebar menus do not move when the content frame is scrolled up and down. For developers frames can also be convenient...
Error handling
An HTML5 (text/html) browser will be flexible in handling incorrect
syntaxIn linguistics, syntax is the study of the principles and rules for constructing sentences in natural languages...
. HTML5 is designed so that old browsers can safely ignore new HTML5 constructs. In contrast to HTML 4.01, the HTML5 specification gives detailed rules for lexing and
parsingIn computer science and linguistics, parsing, or, more formally, syntactic analysis, is the process of analyzing a text, made of a sequence of tokens , to determine its grammatical structure with respect to a given formal grammar.Parsing is also an earlier term for the diagramming of sentences of...
, with the intent that different compliant browsers will produce the same result in the case of incorrect syntax.
External links