Software Vendors:
- PHP - http://www.php.net
- MySQL - http://www.mysql.com
- Apache - http://www.apache.org
- PostgreSQL - http://postgresql.org
Third-Party Applications:
- Smarty - http://smarty.php.net
- PEAR - http://pear.php.net
- PECL - http://pecl.php.net
WWW:
- W3C - http://www.w3c.org
- HTML/XHTML validator - http://validator.w3.org
- Firefox web browser - http://www.mozilla.org/products/firefox/