Mozilla Firefox is a free and open source web browser descended from Mozilla Suite. As of 2011, Firefox had approximately 30% worldwide usage share and was most popular in Germany and Poland. It uses the Gecko layout engine and implements current web standards. Internet Explorer is a series of graphical browsers developed by Microsoft and included in Windows starting in 1995. It was the dominant browser for many years. Safari is Apple's default browser for Mac OS X and iOS, with the first version released in 2003.