Multifox is one of the Grand Prize Winner of Extend Firefox 3.5. It provides a streamlined interface for managing multiple account logins (i.e. Gmail accounts) within a single Firefox session. It allows for easy identity management for all the logged in accounts.

Nowadays, many web applications, web services or website are running on session based authentication and most of them only allow users to login to one account per session or browser.

For example, if you have multiple Gmail accounts for your business emails and personal communication, you will be hard to login to both accounts simultaneously without sign out of another account in different browser’s tabs.

Multifox, a helpful extension for Firefox helps to eliminate the inconvenience by allows users to simultaneously logins to multiple accounts with different user name. Once installed this extension, there will be a new sub-menu “Open in a New Identity Profile” and users can always start their browsing by opening a new Firefox browser as a new identity profile. The total number for profile indication will be shown on the most right side of the URL address bar.

More about this extension,
1. Logins are preserved the same way they are in “regular” Windows. Even if you close the Window or exit the Firefox browser.
2. The identity profile of each window is preserved when Firefox restore the session.
3. The new Windows will inherit the identity profile for the Window they were opened from.
4. Multifox begins from “2″ as its identity profile number because “1″ is consider as the normal Firefox identity profile number.

Information via mozdev.