Mozilla Firefox is an open source web browser with a clean design, providing excellent browsing speed and very powerful customization tools, with just a reasonable footprint on computer resources. Firefox bundles features that include smart bookmarks, spell check, private browsing, a download manager, incremental find, tab grouping (gathers related tabs and organizes them into groups) and several others. In addition to these, Firefox also accommodates a series of tools for developers, such as the DOM Inspector and the Error Console.