An file with .xhtm extension is a webpage file that is written in XHTML. It uses XML 1.0 as its standard implementation and is considered a reformulation of HTML 4. Like XHTML, an XHTM file contains standard HTML tags that follow a more stern XML guidelines. XHTM files are used for publishing website content and commonly use XHTML extension.
You can use web browsers such as Google Chrome, Apple Safari, and Mozilla Firefox to open XHTM files.
The following example of an XHTM document defines the XML declarations.
PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
<html xmlns#"http://www.w3.org/1999/xhtml" xml:lang#"en" lang#"en">
<p>changed to <a href#"http://sample.com/">sample.com</a>.</p>