Terrafirma
Terrafirma is fixed width and needs repairs before it will work as XHTML 1.0 Strict.
This Terrafirma is 6.x-2.1 from 2008-Apr-13, a 45.94 KB download.
page.tpl.php
If you are used to working with PHP and you want to use Terrafirma, consider the following changes.
Replace <html> with:
<html xmlns="http://www.w3.org/1999/xhtml" lang="<?php print $language->language; ?>" xml:lang="<?php print $language->language; ?>">
Leave out the following invalid lines and use the Meta tags module to create the right content.
<meta name="keywords" content />
<meta name="description" content />
Remove target="_blank" from the following line.
Design by <a href="http://www.baruzh.com" target="_blank" title="Baruzh web design & programming">Baruzh</a> | <a href="http://www.nodethirtythree.com/" target="_blank">NodeThirtyThree</a>
In the same line, replace design & programming with design & programming.
You have some unmatched div elements to fix.