Mozilla is planning some major changes in UI for the next version of its Firefox browser, Firefox 4. The new theme for Firefox 4 browser is designed to reflect a modern web browser with “power, simplicity and customizability”. The new theme has been revealed progressively, but still is in work under progress to make new additions and adjustments.There is also a new timeline posted on the project homepage. The design team for Firefox 4 has outlined 4 major goals for the new browser:
- Streamlined UI elements and reduce visual footprints.
- Modernize look and feel.
- Retain visual integration.
- Maintain cross-platform consistency.
Meanwhile Stephen Horlander, a visual designer with the Firefox team has posted some screenshots of the new concepts they are working on:

Firefox 4: Panel Style Notifications

Firefox 4: Linux Notification Panel

Firefox 4: Download Panel