PHP has a rich history and a dominant place on the web. It has achieved much despite language inconsistencies and difficulties. Bjarne Stroustrup once said: "There are only two kinds of languages: the ones people complain about and the ones nobody uses". PHP is one of those languages that everybody uses, yet that's often seen as a good reason to ignore the bad parts and just get stuff done. We're all for getting stuff done, and to that end, the author has used Plain Ol' PHP for many years. It's always bugged him how procedural PHP is, in an ecosystem of OOP libraries and frameworks. So he decided to take a deeper look at building a stronger type system on top of PHP. That's the goal of this book.