Delivering high quality web applications complying with severe project delivery time constraints is still an elusive goal for a software process. In many software projects, development teams often resort to "short cuts" in the software development process avoiding recommended software process disciplines to speed up delivery. The usual side-effects of this ad-hoc approach are low software quality and high maintenance costs. In this paper we empirically address the tension between quality and agility (speed) in web application development describing a set of software disciplines that were added to Extreme Programming to improve web software quality without sacrificing development agility.