From Hooman's presentation at the Cloud Performance Summit at Cloud Connect 2012:
Accelerating applications can mean different things to different people. In web applications, performance is impacted by everything from infrastructure to code to back-end processing to browser capabilities. This can get even more complicated in cloud environments. In this discussion, we'll focus on the issues surrounding the "front-end" performance of the application which includes all interactions between the browser and the app after the dynamic content (the base HTML) has been generated and delivered to the browser. We will discuss the major front-end performance pain points and some strategies for mitigating them (including hidden complications and gotchas), ultimately leading to a better perceived user experience.