Wireless Markup Language(WML):
WML stand for Wireless Markup
Language, based on XML, is a markup language intended for devices that
implement the Wireless Application Protocol (WAP) specification, such as
mobile phones, and preceded the use of other markup languages now used with WAP,
such as HTML/XHTML (which are gaining in popularity as processing power
in mobile devices increases).
WML (Wireless Markup Language), formerly called HDML (Handheld Devices Markup Languages), is a language that allows the text portions of Web pages to be presented on cellular telephones and personal digital assistants (PDAs) via wireless access.
WML is part of the Wireless Application
Protocol (WAP) that is being proposed by several vendors to standards bodies.
The Wireless Application Protocol works on top of standard data link protocols,
such as Global System for Mobile communication, code-division multiple access,
and Time Division Multiple Access, and provides a complete set of network
communication programs comparable to and supportive of the Internet set of
WML is an open language offered royalty-free. Specifications are available at Phone.com's Web site. According to Phone.com, any programmer with working knowledge of HTML, common gateway interface, and Structured Query Language should be able to write a presentation layer using WML. A filter program can be written or may be available from a vendor that will translate HTML pages into WML pages.
The following are some key features of WML as compared to HTML:
WML is a markup language for small, wireless computing devices.
In WML, variables can be defined that store data in string format. In HTML, variables cannot be stored.
The supported image format for WML is WBMP. HTML supports JPEG, GIF and BMP.
A micro-browser is used to run WML markup. A regular browser, such as Internet Explorer, Firefox or Chrome, is used to run HTML markup.
WML follows XHTML specification and is therefore case sensitive. HTML is not case sensitive.
WML has fewer tags compared to HTML.
A deck is a set of WML cards. In HTML, a site is a set of HTML pages.
WML-equipped devices have the following
Display Size: Devices have a small screen size and low resolution; therefore WML has to be capable of rendering content regardless of display size.
Input: Small computing devices do not have a mouse or pointer-based navigation devices. They may have a small numeric keypad or a QWERTY keypad based on whether the device is simple or sophisticated. WML has to be capable of obtaining necessary user input regardless of the limitations of the device.
Processing: They have limited-capacity rechargeable batteries with a low-power CPU and low memory. WML browsers should act like thin clients and perform minimal processing on the device.
Network Capabilities: Small computing devices have a low bandwidth and high network latency. WML has to ensure maximum efficiency in fetching requested Web pages from the server.
Example: print hello world in wml
<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.3//EN" "http://www.wapforum.org/DTD/wml13.dtd">
<card id="card1" title="WML Tutorial">
<card id="card2" title="WML Tutorial">
<p>Welcome to the world of WML</p>