At no other point in the evolution of computing has user experience (as well as attack surface) been so defined by a single piece of software as it is today. Still, no authoritative picture of the true defensive capabilities of the three major web browsers has existed. A team of Accuvant Labs researchers have been hard at work finding real measures for web browser security, and would like to take this opportunity to share some of our initial insight. While there are still questions to be answered, we believe we’ve gained a better view than has previously existed.