Photos: Firefox 4 team try out new user interface
Source:
Mozilla
Firefox 4.0 address bar - How Firefox 4.0 may look
The button at the end of the adress bar turns red once a page has loaded, presumably to give the user the ability to cancel the download.
Do you prefer browser tabs above or below the address bar? Software developers at Mozilla Foundation are trying both.
They are also looking at how to give users more feedback on what the browser is doing when the user types in a URL to go to a website.
These sceen shots show what the Firefox developers are looking at for version 4.0.