Firebug Group Releases 1.2
This latest release of Firebug has been a long time coming, with beta versions stretching back many months. As Resig notes in his blog announcement, users who had not been working with the beta version of 1.2 might be surprised to find that they are being asked which portions of Firebug should be activated. The reason is that activating Firebug has the effect of slowing down Firebug across the board, by what Resig estimates to be 25 percent.
Firebug also provides debugging and profiling support for behind-the-scenes Ajax calls, making it possible for a developer to see what HTTP request was sent to the server, including parameters, and what response was received -- along with an indication of when the call was made, and how long it took to execute.
In the last year, we have seen Firebug turn into a platform with its own plugins. The best-known plugin is almost certainly YSlow, developed by Yahoo's engineering team in order to better understand the source of application bottlenecks.