Firefox 4.0 mock-ups sport a Chrome twist

Mozilla has released mock-ups that show how Firefox 4.0 might look. Two words spring to mind: Google Chrome.

Last week, Mozilla showed some mock-ups for the nearer-term Firefox 3.7 that eliminated the browser's title bar, replacing it with two drop-down menu buttons on the right, just like Chrome has had since its September 2008 debut. The Firefox 4.0 mock-ups show two options, one similar to the 3.7 ideas, and the other taking another step in the Chrome direction.

Specifically, the second Firefox 4.0 mock-up shows the browser tabs on top where once there was a window title bar. That's the same approach that Google picked with Chrome, a screenshot of which you can see below.

Mozilla is seeking comment on the designs, which, the browser developer takes pains to note, are 'for brainstorming/exploration' and aren't final.

Mozilla says advantages of the 'more contentious tabs-on-top concept' include that it saves vertical space and removes visual complexity. On the flip side, it's different, and moving user-interface elements confuses people. Also on the negative side, the missing title bar means people see only a truncated Web page title in the tab.

For Firefox, putting tabs on top meshes conceptually with Electrolysis, aka Content Processes, an under-the-covers change that will make each tab a separate computing process. That carries potential performance, stability and security advantages, but requires more memory.

The Firefox 4.0 mock-ups also show a combination button to the right of the address bar that changes behaviour depending on what the browser is up to. The button can be used to start loading a page whose address has been typed, to stop loading if it's in the process of doing so, and to reload it if it's finished loading.