Wireless Markup Language

Wireless Markup Language (WML) is an HTML-variant markup language as part of the Wireless Application Protocol, an attempt to reinvent the Web for the bandwidth, CPU, and memory limitations of wireless networks and mobile devices. WAP existed around the turn of the millennium, and flopped within a few years.

Curiously, the official site's hub page for WAP specifications links to password-protected documents. However, a slightly older copy can be found by search engine.