I found some interesting things on this topic that I would like to share. First check out this google tech talk video. Steve Souders is also the author of the O’Reilly book ‘High Performance Web Sites: Essential Knowledge for Front-End Engineers’ Yahoo developers network has dedicated section on this topic. YSlow is a Firefox add-on integrated with the popular Firebug web development tool. Click here to download the IBM Page Detailer. I know we got Profiler in Flex Builder 3. Do we have guidelines for high performance Flex 3 applications? I found the livedoc pretty interesting about ‘Using the framework RSL’ There is Optimizer tool also to help. Any comments on this is highly appreciated.