TDD was introduced a while ago, but yet there's no uniform opinion about if it is a useful tool or fancy stuff to brag on.

To make things even worse, there're more than one flavours of TDD: inside-out, outside-in, classicist, mockiest, twitter/ruby-style of TDD...

Let's have a look at the history of TDD, what different schools of TDD are about and what is the modern state of TDD.

Keywords: TDD, BDD, Agile, Refactoring