Are these your current debugging tools? Wouldn't it be nice to see $foo, $bar, and $baz while the code is still being executed? Watch it change, live? And not have it just dumped all over the output of your otherwise beautiful app? We'll install XDebug, set up your IDE to use it (with examples shown for PhpStorm, Netbeans, and ZendStudio), then we'll actually walk through some badly written code that needs to be debugged.