I'm using Debian/Iceweasel for the same reason that I don't use Ubuntu/Firefox and prefer not to have "non-free" in my sources.list. In other words, I fully support free software and the Debian social contract. Anyone who doesn't get this may be using the wrong distro. Personally, I have had no issues whatsoever with IW. :twocents:

I know IceWeasel is FireFox. And it's all about the names that are different. But then, name is a factor for me. I'm using IceWeasel alright, even with a few add-ons from the home of FireFox! And it's where my ego suffers a little: the name FireFox has more appeal to me. Any one may of course think otherwise.

I use both IW and FF because they are both outstanding browsers. I understand all about the philosophical rationale for the re-naming, re-branding of software. I just don't care that much about this issue; I'm a pragmatic person. I use Debian because it functions very well.

I use whatever's supported in the repositories. Iceweasel on Debian and Firefox for Ubuntu.

In about:config set general.useragent.extra.firefox to Firefox/2.0.0.6 (or whatever you're using)

The Mr. Tech local install plugin has a "make compatible" feature you can use to override plugin compatibility checking if you know what you're doing.

It's got a ton of handy power tools that you probobly want

http://www.mrtech.com/extensions/local_install/

The other major difference between IW and FF is pango. The debian package actually supports more languages and character sets than firefox does by using the pango gnome component. This can add overhead and slow down font rendering if you are not in gnome.

If you don't need it, it can be disabled by putting the following line in /etc/iceweasel/iceweaselrc:
MOZ_DISABLE_PANGO=1

There IS a KEY difference!! Please NOTE!!
 

I have noted similar differences myself, having Iceweasel natively installed on my Debian-BASED(THANK YOU Randicus Draco Albus for that correction.) Kali Linux installation..for many reasons which are nicely laid upon the kalilinux site ..page entitled What's New..Anyway. Originally, I wondered why this could possibly be..I'm used to hearing that Firefox is the best browser and for many reasons listed above, I would be keen to believe so myself..but I had to do my research.. and quickly came to this conclusion in regards to security, which is the purpose of using Kali Linux (being a Debian build -- Pentration Testing Platform) ..so I am personally sticking with it..imma weasel my way into this one.. As this is my first post and I do find nice postings on this site I am sorry for any inconsistencies to "post-regulation" ..hope this is the answer someone was looking for:

Iceweasel is a fork [from Firefox] with the following purpose :

backporting of security fixes to declared Debian stable version.
no inclusion of trademarked Mozilla artwork (because of #1 above)

Beyond that, they will be basically identical. (quoting Roberto C. Sanchez post in debian-devel mailing list)

1) Thank you for resurrecting a thread that died six years. :rolleyes:
2) You are correct that Iceweasel is Firefox, but . . .
3) Kali is not Debian. It is a Debian derivative. As such, direct comparisons between the two must be made with caution.

I started using Iceweasel because it had a 64bit version before Firefox did (this was some time ago). The negative side was that Iceweasel's versions tended to lag behind the Firefox ones (at least for Debian Testing). So I installed Firefox alongside of Iceweasel for a while. Basically I use Iceweasel because it gets updated along with all my other packages. I don't need to do anything special. It behaves just like any other package.
jdk

Right now although I like firefox, I prefer to just use iceweasel just so I don't have to manually update.

I think the 64 bit version of Firefox Nightly must have been out a fair amount of time before the 64 bit version of Iceweasel as one of the reasons I ended up using Firefox nightly was to get a 64 bit browser. I still use Nightly now for no other reason than because I can.

Considering that Debian's packages, even in Unstable, lag behind upstream versions, it would definitely be surprising for Debian to have more up-to-date packages than those provided by upstream developers.

Iceweasel is compiled/built on Debian. I do not know what Linux distro Firefox is built on, but Iceweasel runs smoother than Firefox does.

i removed IW and installed FF.

my online bankings constant nag screen about not using a IE or FF compatible browser forced me to remove IW and install FF.

Even compiling with the default flags, I've found Firefox to run smoother for me compared to IW, for my experience at least. But this was back when both were in the 3.6-ish era. Not sure if IW does this, but newer versions of Firefox seem to go crazy with CPU and memory if left running for over a week.

When I used IW, all I had to do was change the user agent to Firefox, and everything worked.