eXtensible HyperText Markup Language
A newer version of the HTML markup language (code) used to create Internet web pages.
Unlike the older HTML, xHTML includes several core features designed specifically with mobile devices in mind. Special versions of xHTML - such as xHTML Basic and xHTML Mobile Profile - are designed specifically for mobile devices. xHTML also includes features that allow a website designed for a full PC to automatically display in a simplified version on a mobile device.
xHTML also adheres to strict XML rules, which makes it much easier for devices with limited processing power (like phones) to understand and display quickly and consistently.
xHTML is a core part of the WAP 2.0 standard, replacing the WML language that was used in WAP 1.x.
While most new phones support xHTML, many older phones only support WML and/or HDML.