Excellent HTTP analysis tool for Firefox: HttpFox (via F5 DevCentral).
Ajaxian reports that CSS transforms will be available in Firefox 3.1.
John Resig blogs about the new Firebug release:
The Script panel (the JavaScript debugger), the Net panel (network monitoring), and Console panel have all seen considerable updates. They're all much more performant and have a huge number of bug fixes.
Firebug changes the way you develop for the web. You won't be able to go back to alert() and background-color: red after you spend some time with it.
Ars Technica reports on tracing, a new optimization added to SpiderMonkey:
They are "getting ready to take JavaScript performance into the next tier" with a radically innovative optimization tactic called tracing that has already produced performance improvements ranging between 20 and 40 times faster in some cases.
Andreas Gal is the researcher behind the new optimization and writes about it:
Traces represent a single iteration through a loop, and can span multiple methods and program modules. If a function is invoked from inside a loop, we follow the function call and inline the instructions executed inside the called method. Function calls themselves are never actually recorded. We merely verify at runtime that the same conditions that caused that function to be activated still hold.
Coach Wei publishes a nice writeup of the recent voting on a features wish list at OpenAjax. Just lifting the limit of 2 concurrent XHR requests and adding native JSON parsing would be huge.
On the same vein it appears that Firefox 3 has an extension for native JSON parsing. It's called nsIJSON. Definitely going to use it in the future.