Page "Handheld Device Markup Language" Paragraph 2

It was originally developed in about 1996 by Unwired Planet, the company that became Phone. com and then Openwave.

HDML was submitted to W3C for standardization, but was not turned into a standard.

Instead it became an important influence on the development and standardization of WML, which then replaced HDML in practice.

( Although HDML is still in use in Japan by KDDI brands such as au, especially for mobile banking solutions.