Source : http://www.xcubelabs.com/
Cell Phone Operating Systems
Around the world, people have come to rely on smartphones. These phones have many of the same basic capabilities of a computer and their operating systems vary depending on the brand of the phone and user preference. While iPhoneOS, Symbian and RIM are the most popular mobile operating systems worldwide, other operating systems, such as Android, are also carving out a market share of their own.
Source : www.cellphones.org