Xdebug

Xdebug is a PHP extension which provides debugging and profiling capabilities. It uses the DBGp debugging protocol.

The debug information that Xdebug can provide includes the following:
 * stack and function traces in error messages with:
 * full parameter display for user defined functions
 * function name, file name and line indications
 * support for member functions


 * memory allocation
 * protection for infinite recursions

Xdebug also provides:
 * profiling information for PHP scripts
 * code coverage analysis
 * capabilities to debug your scripts interactively with a debugger front-end.

Xdebug is also available via the PECL.