Wireless Application Protocol
Wireless Application Protocol (WAP) was a set of standards used to provide a web-like experience on early mobile devices. Pages were authored using Wireless Markup Language (WML), an plain-xml-based alternative to HTML that did not support most of the functionality that web pages allowed.
Partly because of billing concerns and overhype by marketers and also because of the desire to provide a "locked-down" experience on the part of telecoms companies, WAP did not take off in Europe or the United States but was popular in a number of Asian markets. Today, it has mostly been replaced by web pages built using (X)HTML and served over standard HTTP.