iOS (previously iPhone OS) is a mobile operating system extended to support other Apple devices such as the iPod Touch, iPad and second-generation Apple TV Unlike Microsoft’s Windows Phone and Google’s Android. The user interface of iOS is based on the concept of direct manipulation, using multi-touch gestures. Interface control elements consist of sliders, switches, and buttons. Interaction with the OS includes gestures such as swipe, tap, pinch, and reverse pinch, all of which have specific definitions within the context of the iOS operating system and its multi-touch interface. Internal accelerometers are used by some applications to respond to shaking the device (one common result is the undo command) or rotating it in three dimensions (one common result is switching from portrait to landscape mode).
Android, an operating system stands on the Linux kernel, and designed primarily for touchscreen mobile devices such as smartphones and tablet computers.
The user interface of Android is based on direct manipulation, using touch inputs that loosely correspond to real-world actions, like swiping, tapping, pinching and reverse pinching to manipulate on-screen objects. Internal hardware such as accelerometers, gyroscopes and proximity sensors are used by some applications to respond to additional user actions, for example adjusting the screen from portrait to landscape depending on how the device is oriented. Android allows users to customize their home screens with shortcuts to applications and widgets, which allow users to display live content, such as emails and weather information, directly on the home screen. Applications can further send notifications to the user to inform them of relevant information, such as new emails and text messages.
Windows Mobile is a family of mobile operating systems developed by Microsoft for smartphones and Pocket PCs.. Most versions of Windows Much like its desktop counterpart, it comes bundled with a set of applications to perform basic tasks. Windows Mobile applications are strongly encouraged to be optimized for touch screen user interfaces. Windows Mobile has supported third party software the original Pocket PC implementations. Internet Connection Sharing, supported on compatible devices, allows the phone to share its Internet connection with computers via USB and Bluetooth. Windows Mobile support virtual private networking (VPN) over PPTP protocol. Most devices with mobile connectivity include a Radio Interface Layer (RIL). RIL provides the system interface between the Cell Core layer within the Windows Mobile OS and the radio protocol stack used by the wireless modem hardware. This allows OEMs to integrate a variety of modems into their equipment.
BlackBerry OS is a operating system provides multitasking and supports specialized input devices that have been adopted by BlackBerry Ltd. for use in its handhelds, particularly the trackwheel, trackball, and most recently, the trackpad and touchscreen. The BlackBerry platform is perhaps best known for its native support for corporate email, through MIDP 1.0 and, more recently, a subset of MIDP 2.0, which allows complete wireless activation and synchronization with Microsoft Exchange, Lotus Domino, or Novell GroupWise email, calendar, tasks, notes, and contacts, when used with BlackBerry Enterprise Server. The operating system also supports WAP 1.2.
Updates to the operating system may be automatically available from wireless carriers that support the BlackBerry over the air software loading (OTASL) service.
Third-party developers can write software using the available BlackBerry API classes, although applications that make use of certain functionality must be digitally signed.