What it is: An interpreted language most often used for server-side scripting to generate HTML pages dynamically. It can also be used as a stand alone scripting language on many operating systems.
Common complaints: Inconsistent naming conventions for its many functions, security holes, no native support for Unicode, plus it often gets mixed in with presentation code (e.g., HTML, CSS).
Quote: “PHP is the worst language I won't stop using.” ojrac
How to avoid it: If you do any web-based work it’s hard to avoid, but, for starters, don’t work for Facebook, and stay away from Wikimedia, Wordpress, Joomla and Drupal.