Web file written in XHTML, the Extensible Hypertext Markup Language; similar to a .HTML file, but is based on the more strict .XML syntax; allows for a more consistent representation of Web pages across multiple browsers.
XHTML files also use the .XHTML extension.
Program(s) that open xht files
Mac / Windows: Any Web browser
Information from FileInfo.com - The File Extensions Resource.
http://www.fileinfo.com/extension/xht
