I have been aware of EditCSS since September and Simon's Collaborative Redesign of his weblog has been a gentle reminder of what EditCSS can do but I never did get around to installing and playing with it until this weekend when I finally got around to upgrading to Firebird 0.7 and I picked up a few extensions along the way from Texturizer.
If anyone wonders why I leave browser upgrading until late, it is because I have got into the habit of clean installing my browsers and for me this involves uninstalling the browsers, wiping the "Program Files" folder clean and then removing the "Application Data" folder from each of my accounts (the browser recreates the settings), and finally wiping the Registry Keys if I can locate them (I haven't clean installed Opera since version 7.20 due to laziness on my part).
I settled on EditCSS, Live HTTP Headers and the Web Developer Tools because I felt that those were the tools I needed and now I have two great browsers to play with; Opera 7.23 and Firebird.
In my opinion, the Firebird extensions I have settled for has now put it almost on par with Opera which I have always considered feature-rich. It is a pity that Firebird isn't as rich out of the box but I suppose it would be defeating the aims of the browser since it was designed to be Mozilla's little brother.
EditCSS allows Web developers to edit and modify currently loaded stylesheets by loading the CSS in Firebird's sidebar for editing.
Live HTTP Headers adds information about the HTTP headers.
While Web Developer Tools adds a menu and a toolbar to the browser with various web developer tools such as outlining block level images, disabling styles, viewing source codes, validating CSS, HTML, Section 508 Accessibility etc.
Previously, I have only used Firebird for web development though I surf with it on days when I feel guilty of neglecting it but I find that I have been surfing with it for two days now and except for googling1, it is currently meeting my needs; it is just as well that most of my bookmarks are on Opera or I would really be in a quandary.
1Opera has some short cuts I find useful; for example, if I wish to google for wysinwyg, I type g wysinwyg, if I wanted to search the Google Groups, then I type r wysinwyg, in both cases, Opera returns 100 results because I set it up that way.