Xdebug
The following lines detail the options that Vlad sets as the Xdebug setup.
xdebug.remote_enable=1
xdebug.remote_port=9000
xdebug.remote_handler="dbgp"
xdebug.remote_connect_back = 1
xdebug.profiler_enable=0
xdebug.profiler_output_dir=/tmp/xdebug_profiles
xdebug.profiler_enable_trigger=1
xdebug.profiler_output_name=cachegrind.out.%p
This allows for both interactive debugging and profiling using Xdebug.
The Xdebug profiler needs to be activated by passing the XDEBUG_PROFILE variable as a GET or POST parameter. When passed during a page load this will generate a file starting with cachegrind.out. in the /tmp/xdebug_profiles directory. Open these files with a program like KCachegrind to see data on how your application is performing.