Mike Walsh

phpHtmllib is a set of PHP classes and library functions to help facilitate building, debugging, 
and rendering of XML, HTML, XHTML, WAP/WML Documents, and SVG (Scalable Vector Graphics) images 
as well as complex html ‘widgets’. It provides a mechanism to output perfectly indented/readable 
tags, and a programmatic API to generating tags on the fly.
More information can be found on the <a href="http://michaelwalsh.org/wordpress/wordpress-plugins/phphtmllib/" rel="nofollow ugc">phpHtmlLib</a> 
plugin page.

phpHtmlLib

The phpHtmlLib library contains a set of PHP classes and library functions to help facilitate…

Allan Collins

Is your website up to W3C HTML coding standards? This plugin will allow you to test each page or post on your site against the W3C Validator.
Want to contribute? Fork it: https://github.com/allan23/validated

Validated

This plugin will allow you to check your pages/posts HTML against the W3C Validator.

phpHtmlLib vs Validated