Here are some interesting charts showing the statistical data gathered over the 3 months starting May 1 2010, up to August 1 2010 on Dev4Press.com: browsers and operating systems used by visitors. And for browsers, data is much different than world wide data.
After the first part of the benchmark of WordPress 3.0 versus 2.9.2, here is the second part focusing on the admin section of the WordPress and the execution on the client side. Part 3 is coming in a few days and it will be dedicated to testing on the blog side of the WordPress.
Whenever you use JavaScript powered application, data is usually transported using AJAX from the server to the client side. During that process, errors can occur on the server side to cause application to fail. Firebug is extension for Firefox that can help us track these problems.
I know that many people will be offended by this post, but I know that I am not the only one having so many troubles with Firefox. For years Firefox was getting worse with every new version. Before you start throwing rocks at me, please read the post to find out why I hate Firefox, and why they need to release 64bit version, yesterday.