The Debug component provides tools to ease debugging PHP code.
Php Debugger to run in terminal to debug your code easily.
Silex service provider to handle PHP errors, dump variables, execute PHP code remotely in Google Chrome
Helps you debug Behat scenarios by stopping execution in between steps
Emulates the SQL query constructed by PDO. The magic behind: A simple function that combines your parameters and the raw query. Not perfect, but does the job.