Thus, using this tool (Firebug; Mozilla Firefox Add-on), a Web 2.0 developer can very easily analyze which user action creates how much traffic behind the scenes using AJAX, which user action is performed at the client side, how much requests are generated for each user action, what’s the size of request / response for a user action and other such stuff related with the debugging of Java Script, modification in CSS and DOM Inspection. So, I would recommend every web developer who is involved in evaluating the different UI controls to be used in web applications or other such tasks related to improving the overall user experience of a web application to try this add-on; FireBug on FireFox. A snapshot of this tool, is shown below.
There is in add-on in FireBug in the name of YSlow. That provides information on how to improve the performance of your website. This add-on is by Yahoo Developer Network and automates the verification of all the Consideration for High Performance Websites in this single tool. This not only verifies and ranks the website against the said Best Practices for High Performance websites, but also provides information on what’s wrong and what you can do to improve the performance. A snap shot of the YSlow Addon of Firebug is shown below.
Something similar but with relatively lesser features is the IE Developer Toolbar, which Internet Explorer centric Web 2.0 developers, should definitely have a look at and experiment with. [Added: 22nd April 2008]
Another easy to use tool out there for Internet Explorer to perform a similar analysis of web applications (a bit buggy on I.E 6 at least on my machine) is the Web Development Helper by Nikhil Khotari. Below is the snapshot of that.