Firebug is a free and open-source, complete and powerful Web development auxiliary plug-in for Mozilla's Firefox. The same as Chris Pederick's Web Developer, it added plentiful website designing, developing and testing tools at our fingertips. Web developers can use it to debug, edit or even delete HTML, CSS, DOM, and JavaScript code of any website.

Artisteer is a visual website template designer, with which you can create WordPress theme or other professional website templates (including all details) in a few minutes. And the whole process is completely WYSIWYG, users do not need to master any coding or CSS knowledge.