Mozilla FireFox 4 is hitting the marketplace March 22nd. It’s staring at some stiff competition with Internet Explorer 9 and Google Chrome 10 on the horizon as well, but FireFox 4 provides an updated user interface that Mozilla says is both sleeker and easier to use. Firefox 4 also lets users synchronize settings, passwords, bookmarks, history and open tabs with other devices, and it allows users to drag and drop open tabs into groups that can be named and arranged. Lastly, there’s a new and improved way to manage Firefox add-ons. While March 22nd is the current launch date, Mozilla does warn that there is the potential for a delay.