A few day ago, I have posted about Firefox 3.7 mockups which proposed that Aero Glass will be made available in Windows Vista and 7. Now, mockups for Firefox 4.0 has been discovered on the Mozilla Wiki, which shows how the next gen of Firefox might look like. It seems that the company is struggling to choose between two primary designs: tabs-on-bottom and tabs-on-top. Tabs on bottom is the current normal in Firefox, While the tabs-on-top will create almost exactly the same look of Google Chrome.

Version A - Tabs-on-Bottom

Possibly add a Bookmarks widget as an upfront replacement for the Bookmarks menu/Bookmarks toolbar (option to turn those on would remain).

Version B - Tabs-on-Top

The more contentious Tabs-on-Top concept.

Positives

• Save Vertical Space
• Efficiency/Remove Visual Complexity - Right now the tabs have to be connected to something. So we are adding an extra visual element for them to connect to.
• Shorter Mouse Distance to Page Controls

Negatives

• Breaks Consistency/Familiarity - Moving things confuses existing users.
• Title is MIA - With the space removed from the titlebar you only get the truncated version in the tab.
• Longer Mouse Distance to Tabs - Takes longer to mouse to a tab.
• Lost Space - Sandwiched in between the application icon and the window widgets you lose some space.

Combo Stop/Refresh/Go Button.

Attached at the end of the location bar.

• Turns green when you start typing.
• Blends with the location bar when at rest.
• Turns blue on hover.
• Turns red when a page is loading.

The proposed iconography is mostly colorless. Adding color to these temporary action driven buttons will make it more obvious something is going on.

If you liked this post, Subscribe to RSS or Follow me on Twitter