Without knowing how the mobile web started, it's impossible to appreciate the ease with which we can develop for mobile devices. If the mobile web works at all, it is a feat in itself, and it took the convergence of several technologies to make it all possible.
The Nokia 9000 is, arguably, the first mobile web device. Developed by Nokia in 1996, this phone weighed in at a whopping 14 ounces (397 g), and was powered by an Intel i386. It was equipped with a 640 x 200 pixel gray-scale LCD. This phone allowed owners to send faxes, send and receive email, and surf the web. It also came equipped with terminal and Telnet applications for accessing mainframe systems.
During this time, Nokia was in competition with Ericsson and others for control of the mobile data space. The Nokia 9000 was designed to use Narrow Band Sockets, a communication protocol developed and championed by Nokia. Information that was to be displayed on the Nokia 9000 was returned to the phone using Tagged Text Markup Language (TTML), a markup language that content providers could use to optimize web pages for mobile devices by removing extraneous information from the display and transmission.
At about the same time, Ericsson had developed Intelligent Terminal Transfer Protocol (ITTP). ITTP was Ericsson's proprietary markup for the mobile web.
It became evident to the major phone manufacturers that market fragmentation was going to be inevitable unless they could develop a common standard to enable the mobile web on their devices.
On June 26, 1997, Nokia, Ericsson, Motorola, and Unwired Planet publicly announced that they would be cooperating on a Wireless Application Protocol (WAP). WAP 1.0 was to be an open protocol that any vendor could implement, and this new protocol would enable mobile device manufacturers to connect to the IP-based world of the Internet from mobile devices that had an inherently high rate of data loss during communication.
Wireless Markup Language (WML) became the standard for designing applications that ran on WAP 1.0, and was a second-generation derivative of HTML and XML.
However, WAP and WML had some shortcomings. The protocol and companion markup languages were designed for very slow data networks and very limited display capabilities. If your device had limited data input capabilities and a low-resolution display, then WML served you well, but with the advent of smart phones and mobile web browsers, derivatives of their desktop counterparts, WAP 1.0 and WML became less relevant.
As the convergence of mobile phones and PDAs gained momentum, new standards were needed to support the growing use of web-enabled mobile devices. To support the new browsers that began to ship with mobile devices, a new markup language was required.
In 2001, eXtensible HyperText Markup Language Mobile Profile (XHTML MP) was adapted from XHTML Basic by the WAP Forum (now part of the Open Mobile Alliance) to replace WML as the default protocol for WAP.
Note
While WAP became the standard in the United States, United Kingdom, and Europe, the standard in Japan, i-mode, was developed by NTT DoCoMo.
The new standards were short-lived. Today, most mobile devices ship with browsers supporting the latest HTML standards including HTML5 and CSS3, but it is still a good practice to deliver content to target the broadest market possible.