I like these “Best” lists that you find on blogs, so I thought I should at least start contributing my own. And to begin with, my own list of swizzy Firefox add-ons that will help the humble developer.  They’re all Firefox 3 compatible and they’re all free.

In no particular order (other than, erm, alphabetical. Which is an order)…

Firebug
A Yahoo provided plug-in that allows you to edit, debug, and monitor CSS, HTML, and JavaScript live in any web page. Once installed you can couple this with YSlow, a plugin for Firebug, which puts into practise Yahoo’s very own website performance principles - displaying how well the page does and providing a breakdown into what makes up the page download.

IE Tab
With a click of an icon you can switch Firefox’s rendering engine to IE and back again. Useful for those quick cross-browser tests.

LinkChecker
This scans the current web page and highlights each link it finds according to whether it was valid or not - a great way to quickly check link validity on a page.

Live HTTP headers
Allows you to see the header information sent by a web page - particularly handy for checking on compression, caching, cookies and the like.

MeasureIt
This is a quick and simple measurement tool. Normally, I’d recommend standalone apps for this kind of thing so they’re not restricted to the browser, but this does this particular job so well, it’s still a requirement.

RankChecker
When it’s time to keep an eye on your SEO, this is invaluable. You type your chosen search terms into the RankChecker screen and it will display, for a number of popular search engines, where your site came in the results. Great for monitoring whether your SEO is working or not.

Screen grab!
This does a single job but, god, does it well. It takes screen shots from the browser. You can either take an area, the current visible portion or the whole page (whether currently on screen or not). You can then save the results or stick it on your clipboard.

SEO For Firefox
This displays various SEO information about the site - PageRank, links, etc

Split Browser
This is a new one that I’ve come across when I had a specific requirement. Basically, this lets you split the Firefox screen into multiple “windows” into which you can load different pages. In my case I found this invaluable when comparing two pages side-by-side (an existing version of a website and a new, modified version).

Web Developer
What more can be said about this? If you could only have one add-on, this should be it, with links and tools to everything you could imagine. My most-used part of it is the ability to switch off web page components, such as JavaScript and images. Brilliant.

Yep, enough of my critical plugins are now working on Firefox 3 that I installed it. Hurrah.

But, of course, this is me so thing went wrong.

First of all, it didn’t seem to find my bookmarks correctly, so I decided to get Foxmarks to simply download everything from it’s server. Oops. Now the smart bookmarks have gone.

http://forums.mozillazine.org/viewtopic.php?f=23&t=668145

to get the ’smart’ bookmark folders back, open up about:config and set browser.places.smartBookmarksVersion to 0 then restart Firefox.

Next, I found that the Mozilla plug-ins site was not detecting my version of Firefox correctly.

http://support.mozilla.com/tiki-view_forum_thread.php?locale=en-US&forumId=1&comments_parentId=67725

Enter about:config in the Location bar

Type general.useragent in the “Filter”

Right-click each of the general.useragent preferences and choose “Reset” from the context menu.

For the time being, that appears to be it. Hmm.

Firefox 3 was officially released last night. They were hoping to get 2 million downloads in 24 hours but within about 2 hours they seemed to have 2.5 million. Not bad going.

It also meant that getting hold of the download was difficult. Never-the-less I was able to and tried it out.

Now, I tried the Beta some time ago but didn’t use if “properly” (I rang it alongside my current version 2) because of the lack of compatible plugins. Because of the imminent launch yesterday of the final version, I was expecting this to be mainly resolved. I was wrong.

I have 23 add-ons. 2 are bundled with Firefox and Skype. Of the other 21, only 10 are currently compatible with Firefox 3, leaving 11 not.

So, I re-installed Firefox 2 again (although it didn’t initially work being installed over the top of FF 3, so I uninstalled it and then re-installed FF 2. That worked).

Once a reasonable number (plus those that I deem essential) are compatible, I’ll re-install. But until then…

When Microsoft Update thinks I’m using a Mac. Yes, last night I went to get some updates from Microsoft Update and I got the message…

Thank you for your interest in obtaining updates from our site.

This website is designed to work with Microsoft Windows operating systems only.
To find updates for Microsoft products that are designed for Macintosh operating
systems, please visit http://www.microsoft.com/mac/.

Nice. I was using Internet Explorer 7 on Windows XP MCE SP3.

It knows which system I’m using from the “user agent” but one of many websites which displays your current user agent information, showed that I was happily using Windows. Weird.

Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) ; .NET CLR 1.0.3705; .NET CLR 2.0.50727; .NET CLR 1.1.4322; Media Center PC 4.0; .NET CLR 3.0.04506.30; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022; WTClient2)

Weirder still was that if I used IE Tab in Firefox, the page would appear without a problem. As IE Tab simply uses Internet Explorer but in Firefox, it shouldn’t have been any different. Again, I checked the user agent and that was the same as running it under IE normally.

Double weird.

Anyway, after a reboot even IE Tab stopped working.

Googling the issue found that most people seemed to have Spyware or Virus’. In panic, I did a check but found nothing. However, I also came across a Microsoft blog on how to reset all of IE 7’s settings - I tried that and Microsoft Update is now working again.

Before, I talked about installing the beta of Internet Explorer 8 for website test purposes. Unfortunately, and I covered this also, it doesn’t sit with existing IE installations, unlike Firefox which you simply install into a seperate folder.

Now, and this comes from experience, all may not go well when two Firefox installations try to share a profile - particularly if one of those Firefox installations may break add-ons. So, having installed IE8 I thought it was only right to also try out the current beta of Firefox 3.

So, my workaround for this is to ensure you have seperate profiles and that each version of Firefox definitely uses the one it should do. Here’s what I did…

• Find your existing Firefox installation folder - usually C:\Program Files\Mozilla Firefox - and open up a command window
• Run firefox.exe -ProfileManager - the profile window will appear
• Ensure your current profile is named something appropriate. I changed it from default to David
• I then created a new profile named Test and closed the profile window down.
• Now change your current Firefox shortcut so that it specifically launches your original profile. In my case, this was "C:\Program Files\Mozilla Firefox\firefox.exe" -P "David"
• I now downloaded the Beta 4 of Firefox 3.
• Run the downloaded program and select Custom installation - ensure it installs into a different folder than your current Firefox application. In this case it defaulted to C:\Program Files\Mozilla Firefox 3 Beta 4
• Once installed, de-select the option to launch the new Firefox installation.
• Find the new shortcut and change this to point to your newly created second profile. In my case this was, "C:\Program Files\Mozilla Firefox 3 Beta 4\firefox.exe" -P "Test"

And that’s it. Each version of Firefox will launch with it’s own profile and you can tinker about with your Beta installation all you like without affecting your normal browser profile.