Firefox 3.5 is barely fresh out of the door, but we're already looking ahead to the next release of everyone's favourite browser (except for me, that is). It's called Firefox 3.7 for now, and the discussion on the proposed user interface overhaul is currently in full swing.
The Firefox team will be embracing Aero Glass on Vista and Windows 7, which is definitely a step forward. Sadly, though, they seem to be going a bit overboard with all the widgets, buttons, and other frivolities that confuse me. The individual pieces of the puzzle look good, it's just that there are too many different pieces that don't look very coherent, and are thrown all over the place. Barely any two buttons are the same, which doesn't strike me as good UI design; there's also a lot of wasted space. A good thing is that it also works well when Aero Glass is turned off.
Windows XP users surely aren't left out in the rain by the Mozilla, as the implemented more or less the same design as above to the default Windows XP themes. The theme, as well as the button layout, do not copy over very well to XP's Luna theme - and I wouldn't dare to think how it would look on Windows Classic, which is - I surely hope so - the preferred theme on most Windows XP boxes.
The mockups for Firefox 4.0 is where it gets really interesting. As it turns out, the Firefox UI team is experimenting with a Chrome-like tabs-on-top look, but they remain unsure whether or not tabs-on-top is actually the way to go. As a result, they designed two variants: tabs-on-top, and tabs-current.
Both variants again suffer a bit from what I call visual overload - too many different types of buttons, too many different colours, and they're all over the place. It reminds me a lot of the current Internet Explorer interface, and that's a bad thing. They are, however, taking a lot of cues from Google Chrome's interface, but while they can copy certain aspects of Chrome's UI, they failed to grasp the overall idea: reduce the chrome as much as possible, allowing you to focus on what really matters: content (web pages). The mockups are too busy for my taste, drawing my attention towards the user interface elements instead of towards the content.
Still, it's good to see that the Firefox team is looking into improving the user interface of their highly successful browser. Even if you don't like where these mockups are going, Firefox' flexibility will most likely allow you to go back to the current interface quite easily.
An issue I haven't seen addressed yet is how these themes will copy over to the Linux and Mac OS X worlds. I'm sure mockups for these platforms will pop up soon enough.