The VR Trace interface displays important server side data to make debugging your php programs a snap. The plugin allows you to send additional data to the interface by calling the vr_trace() function within your program. This allows you to keep your debugging data out of the main html flow, which prevents your printed data from breaking the layout. So stop using print_r and echo and start using vr_trace instead.
VR Trace also has a default global set. View all the stored data from $GLOBALS, $_SERVER, $_GET, $_POST, $_FILES, $_COOKIE, $_SESSION and more from a convenient dropdown.