While the official Mozilla effort still was working on the unified browser and e-mail software package dating back to the Netscape era, Dave Hyatt and Blake Ross began work on a simplified browser initially called Phoenix. This is the logo for Phoenix 0.1, the first milestone of the browser. It was released in September 2002, but the name triggered a trademark infringment challenge from Phoenix Technologies.
Mozilla dropped the Phoenix name in favor of Firebird, version 0.7 of which is shown here. It includes the built-in search box in the upper-right corner that, by leading to searches and search advertising at Google, provides the lion's share of Mozilla's revenue. The Firebird name also ran into trouble because there was an an open-source database project of the same name, leading Mozilla eventually to move to Firefox.
Firefox 3.7, scheduled to arrive in the first half of 2010, is designed to fit in better with the look and feel of Windows Vista and Windows 7. It also replaces the menu bar with two menu buttons, removes the home page button and substitutes a home tab, and merges two buttons, stop and reload, into one.
This mockup shows a design for Firefox 4.0. It loses the menu bar, replacing it with drop-down menu buttons in the upper right. It also unifies the address box and search box. And it puts the tabs across the top, a feature expected to be optional. All three elements are standard in Chrome, Google's browser.