Best free webmaster tools?

I use zen-cart to build my own e-commerce site and use seoquake add-on for optimization purpose.

if you want you can try wordpress, drupal and joomla. Most site owners used these scripts in their sites. you can try them and look what is best for you. which suits your needs.

Wordpress Theme tools:
I used the following free tools to develop my theme.

* GIMP – Free image editing software
* Cooltext online tool to create buttons and logo
* Notepad to edit css, php files
* W3C validator for XHTML and CSS validator
* Firebug add-on to inspect and modify stylesheets
* Browsershots – online service to check older browser compatibility
* YSlow addon for Firebug to test the page download speed
* SubmitExpress metatag analyzer to check the meta tags

Thanks for these tips.