The concept of mobile operating system began way back in 1996 with the invention of Palm tops.
Palm OS was the first mobile OS. Many versions of this were launched until 2000 when pocket PCs were introduced by Microsoft. But it was not until 2007 when iPhone was first released, that Palm tops vanished completely.
Along with the iPhone entered Android and Blackberry OS. Since 2008 more mobile operating systems have been launched namely - Symbian, HP web OS and Samsung Bada.
Meanwhile, Android, Blackberry, Windows Phone and iPhone have released higher versions of their OS.