• Migrating from PHP 5.6.x to PHP 7.0.x

How To Debug PHP Code And Useful PHP Debugging Tools

• Gubed PHP Debugger：http://gubed.mccabe.nu/
• PHP Debug：http://www.php-debug.com/www/
• DBG：http://www.php-debugger.com/dbg/
• PHP Dyn：http://sourceforge.net/projects/php-dyn/
• Xdebug：http://xdebug.org/
• Webgrind：http://code.google.com/p/webgrind/
• MacGDBp：http://www.bluestatic.org/software/macgdbp/
• Advanced PHP Debugger：http://pecl.php.net/package/apd

How to Debug PHP Using Firefox with FirePHP

How to Debug in PHP

Debugging PHP using Eclipse and PDT

Debugging PHP with Xdebug

Debug PHP with DBG Wizard

http://code.google.com/p/php-snow/

Snow is a little language that compiles to PHP. It has its own syntax inspired by Python, Ruby, Go and Scala that strives to be DRY, clean and easy to read as well as write. For those familiar with Coffescript you could say that Snow is to PHP what Coffeescript is to Javascript.

http://plog.longwin.com.tw/programming/2009/02/06/php-rfc-compliant-email-regex-validate-2009

http://plog.longwin.com.tw/programming/2007/11/30/validate_email_use_dns_mx_2007

http://www.techotopia.com/index.php/PHP_Essentials

http://godbit.com/article/introduction-to-php-coding-standards

http://devzone.zend.com/node/view/id/627

http://immike.net/blog/2007/08/15/

http://ioreader.com/2007/08/17/

http://www.smashingmagazine.com/2009/01/20/50-extremely-useful-php-tools/

http://www.search-this.com/2007/08/13/yahoo-job-interview-questions-part-1/

http://www.search-this.com/2007/08/27/yahoo-job-interview-questions-part-2/

http://www.php.lt/benchmark/phpbench.php

40 Tips for optimizing your php code

http://www.elated.com/articles/object-oriented-php-for-absolute-beginners/