The blue icon to the top left shows that this is Minefield[1] (codename for nightly builds of Firefox). Also, it has a dropdown arrow, showing that this is probably using the Hide Menu Bar[2] addon. The lack of usual menubar/chrome of the browser can be explained by the use of Awesomewm[3] or dwm[4]. Firefox 4+ builds all have the same tabbing as in the screenshot. Also, the bookmarks toolbar has been dragged to the same line as the addressbar and all bookmarks and bookmark folders have no name, thus only showing their favicons, which is the default behavior. Also, the grandparent comment has apparently moved the status bar to the top, on the same level of the tabs. This is new to me, and maybe the default behavior in current nightly builds of Firefox.

If I may be so bold, I'd wager this author is using Arch Linux, since awesomewm is very popular with that group of users, and because of the rolling-release cycle nature of Arch, resulting in the latest builds of Firefox.

[1]: http://www.mozilla.org/projects/minefield/

[2]: https://addons.mozilla.org/en-us/firefox/addon/hide-menubar-...

[3]: http://awesome.naquadah.org/

[4]: http://dwm.suckless.org/

> Also, the grandparent comment has apparently moved the status bar to the top, on the same level of the tabs. This is new to me, and maybe the default behavior in current nightly builds of Firefox.

That's not the status bar, it's a couple of toolbar buttons dropped on the right side of the tabbar. Minefield doesn't have a status bar anymore. It's renamed to "Add-on Bar" and is used only for placing addons' icons.

Sweet, didn't know about the new change in Minefield. Thanks for the heads up!

Firefox 4 (out-of-the-box and on the surface) is going to look more and more like the current Chrome. A new breed of Firefox extensions will surface very soon to hack away a lot of ui stuff back to 3.6 (Namoroka) branch. ("classic" status bar, "classic" tabs, things like that...)

Close! It's actually Xmonad on CrunchBang Linux and I'm using the Compact Menu addon. There is no status bar, I just placed the icons to the tab bar.

Just by moving stuff around. Addons to the tab bar, bookmarks to the address bar. I used an addon to compress the menu and moved it to the tab bar as well. I then removed the empty menu and bookmarks toolbars. I'm using Firefox 4. Oh and having no window decorations helps too.

https://addons.mozilla.org/en-us/firefox/addon/compact-menu-...

Firefox 4 (Minefield) has the option to stack tabs on top.

Does it do that always though, or only in full-screen? The 4 betas do it in full screen on Windows, never explored in OSX. I essentially never browse full-screen, there are too many 960px fixed-width websites out there, so it's just wasting 500px where I can have other things open.

On Windows, Minefield nightly does it in normal mode. In full-screen mode you don't see any ui element at all. By the way, "Tabs on Top" is an option accessible by main context menu. You can enable/disable it just like menubar and bookmarks toolbar.

sorry, meant "maximized". Full-screen is a bit different, yes.

I don't know that I've seen the "tabs on top" preference... they're always on the top, with plugins doing side-tabs. I'll look for it some time though.

Yes, you can see them also with maximized window. Here is a screenshot to find the option: http://i.imgur.com/6JJcU.jpg

I think they enabled it by default a while back to further match Chrome ui.