BlueHat

BlueHat (or Blue Hat or Blue-Hat) is a term used to refer to outside computer security consulting firms that are employed to bug test a system prior to its launch, looking for exploits so they can be closed. Their role involves searching for weaknesses or security gaps that could be exploited, and their aim is to rectify and close these potential vulnerabilities prior to a product or system launch. In particular, Microsoft uses the term to refer to the computer security professionals they invited to find the vulnerability of their products, such as Windows.

Blue Hat Microsoft Hacker Conference
The Blue Hat Microsoft Hacker Conference is an invitation-only conference created by Window Snyder that is intended to open communication between Microsoft engineers and hackers. The event has led to both mutual understanding and the occasional confrontation. Microsoft's developers were visibly uncomfortable when Metasploit was demonstrated.