iThemes

Chris Wiegman

Selecting “Open link in a new window” in the builtin WordPress WYSIWYG editor breack XHTML strict compliance by adding the attribute target=”_blank” to anchor tags. This plugin fixes the problem by replacing the target attribute with a common class attribute and then using a simple jquery script to open the link in a new window. This method allows for correct validation using XHTML 1.0 Strict.
<h3>License</h3>
Released under the terms of the GNU General Public License.

Replace Anchor Target

Replaces target="_blank" attribute for XHTML Strict compliance.

Roland Rust

It functions as a frontend for the Markup Validator Web Service API on http://validator.w3.org. Stylesheets are checked as well.
Languages available: 
+ english 
+ deutsch(german)

Batch Validator

This plugin performs a batch markup validation check over your entire WordPress website.

Replace Anchor Target vs Batch Validator