Wireless Markup Language (WML), based on

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing data. It defines a set of rules for encoding electronic document, documents in a format that is both human-readable and Machine-r ...

, is an obsolete

markup language A markup language is a Encoding, text-encoding system which specifies the structure and formatting of a document and potentially the relationships among its parts. Markup can control the display of a document or enrich its content to facilitate au ...

intended for devices that implement the

Wireless Application Protocol Wireless Application Protocol (WAP) is an obsolete technical standard for accessing information over a mobile cellular network. Introduced in 1999, WAP allowed users with compatible mobile devices to browse content such as news, weather and sp ...

(WAP) specification, such as

mobile phones A mobile phone or cell phone is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones ( landline phones). This radio ...

. It provides navigational support, data input, hyperlinks, text and image presentation, and forms, much like

HTML Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets ( ...

(Hypertext Markup Language). It preceded the use of other markup languages used with WAP, such as

XHTML Extensible HyperText Markup Language (XHTML) is part of the family of XML markup languages which mirrors or extends versions of the widely used HyperText Markup Language (HTML), the language in which Web pages are formulated. While HTML, pr ...

and HTML itself, which achieved dominance as processing power in mobile devices increased.

WML history

Building on Openwave's HDML, Nokia's "Tagged Text Markup Language" (TTML) and Ericsson's proprietary markup language for mobile content, the

WAP Forum OMA SpecWorks, previously the Open Mobile Alliance (OMA), is a standards organization which develops Open standard, open, International standard, international technical standards for the mobile phone industry. It is a Nonprofit organization, nonp ...

created the WML 1.1 standard in 1998. WML 2.0 was specified in 2001, but has not been widely adopted. It was an attempt at bridging WML and XHTML Basic before the WAP 2.0 spec was finalized. In the end, XHTML Mobile Profile became the markup language used in WAP 2.0. The newest WML version in active use is 1.3. The first company to launch a public WML site was Dutch

mobile phone A mobile phone or cell phone is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones ( landline phones). This rad ...

network operator Telfort in October 1999 and the first company in the world to launch the Nokia 7110. The Telfort WML site was created and developed as side project to test the device's capabilities by a billing engineer called Christopher Bee and National Deployment Manager, Euan McLeod. The WML site consists of four pages in both Dutch and English that contained many grammatical errors in Dutch as the two developers were unaware the WML was configured on the Nokia 7110 as the home page and neither were native Dutch speakers.

WML markup

WML documents are XML documents that validate against the WML DTD ( Document Type Definition)WAP Forum
"Wireless Markup Language (WML) 1.3 Document Type Definition"
/ref> . The W3C Markup Validation service (http://validator.w3.org/) can be used to validate WML documents (they are validated against their declared document type). For example, the following WML page could be saved as "example.wml":

This is a sample WML page.

A WML document is known as a "deck". Data in the deck is structured into one or more "cards" (pages), each of which represents a single interaction with the user. WML decks are stored on an ordinary

web server A web server is computer software and underlying Computer hardware, hardware that accepts requests via Hypertext Transfer Protocol, HTTP (the network protocol created to distribute web content) or its secure variant HTTPS. A user agent, co ...

configured to serve the text/vnd.wap.wml

MIME type In information and communications technology, a media type, content type or MIME type is a two-part identifier for file formats and content formats. Their purpose is comparable to filename extensions and uniform type identifiers, in that they ide ...

in addition to plain HTML and variants. The WML cards when requested by a device are accessed by a bridge ( WAP gateway), which sits between mobile devices and the World Wide Web, passing pages from one to the other much like a proxy. The gateways send the WML pages on in a form suitable for mobile device reception ( WAP Binary XML). This process is hidden from the phone, so it may access the page in the same way as a browser accesses

, using a URL (for example, http://example.com/foo.wml). (Provided the mobile phone operator has not specifically locked the phone to prevent access of user-specified URLs.) WML has a scaled-down set of procedural elements, which can be used by the author to control navigation to other cards. Mobile devices are moving towards allowing more

and even standard HTML as processing power in handsets increases. These standards are concerned with formatting and presentation. They do not however address cell-phone or mobile device hardware interfacing in the same way as WML.

WML capability in desktop browsers

The Presto layout engine (used by

Opera Opera is a form of History of theatre#European theatre, Western theatre in which music is a fundamental component and dramatic roles are taken by Singing, singers. Such a "work" (the literal translation of the Italian word "opera") is typically ...

before its switch to Blink) understood WML natively.

Mozilla Mozilla is a free software community founded in 1998 by members of Netscape. The Mozilla community uses, develops, publishes and supports Mozilla products, thereby promoting free software and open standards. The community is supported institution ...

-based browsers (

Firefox Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements curr ...

(before version 57),

SeaMonkey SeaMonkey is a free and open-source Internet suite. It is the continuation of the former Mozilla Application Suite, based on the same source code, which itself grew out of Netscape Communicator and formed the base of Netscape 6 and Netscape ...

, MicroB) could interpret WML through the WMLBrowser add-on.

Google Chrome Google Chrome is a web browser developed by Google. It was first released in 2008 for Microsoft Windows, built with free software components from Apple WebKit and Mozilla Firefox. Versions were later released for Linux, macOS, iOS, iPadOS, an ...

can also interpret WML via two extensions: WML and FireMobileSimulator.

Criticism

References

External links

Technical Specifications at the WAP ForumXHTML-MP Authoring PracticesOpen Mobile Alliance
{{Authority control Wireless Application Protocol Open Mobile Alliance standards XML markup languages