This is a 60 minute presentation I gave at DDD7 conference in the UK on 22nd November 2008 on Microsoft Pex. Is unit testing about to have a major change? Pex is a project from Microsoft Research which automatically generates a traditional unit testing suite with high code coverage from hand-written parameterised unit tests. In this session, Ben explores the Pex framework, explaining the approach the framework takes and how it computes the test inputs based on your programs execution. Ben demonstrates how to use the framework and how it could potentially change the way we write unit tests.