But not all the changes are available on Mac and Linux yet. For now, major visual changes including the move of tabs to the top of the window and implementation of the Firefox button for quick access to commonly-used actions are only available on Windowns, according to MacRumors.
Several other key changes include new add-ons manager, which gives users more space to manage add-ons, HD video, privacy improvements (when a plugin crashes or freezes, users can resume browsing by simply refreshing the page) and improved responsiveness at start-up and during page loads.
Firefox 4 also includes a number of under-the-hood enhancements to assist web developers with their projects.
Finally, the new beta integrates a new feedback add-on that allows users to quickly send input back to Mozilla.