My expertise is in the area of web applications, using, for now, PHP MVC Frameworks (Zend Framework 1 and 2, Yii Framework, and adapting pretty fast to any similar Framework).

I’ve been using PHPUnit as a tool for TDD (Test Driven Development) and I’m currently looking into using and implementing Behat Framework for BDD (Behaviour Driven Development).
If TDD and BDD sounds new and weird to you, they are just tools that helps developers ensure code quality and following project specifications while developing the code.