Maemo

Maemo is a software platform developed by Nokia for smartphones and Internet Tablets. It is based on the Debian Linux distribution.
The platform comprises the Maemo operating system and the Maemo SDK.
Maemo is mostly based on open source code, and has been developed by Maemo Devices within Nokia in collaboration with many open source projects such as the Linux kernel, Debian, and GNOME. Maemo is based on Debian GNU/Linux and draws much of its GUI, frameworks, and libraries from the GNOME project. It uses the Matchbox window manager, and the GTK-based Hildon as its GUI and application framework.
The UI in Maemo 4 is similar to many handheld interfaces, and features a "Home" screen, which acts as a central point from which all applications and settings are accessed. The Home Screen is divided into areas for launching applications, a menu bar, and a large customisable area that can display information such as an RSS reader, Internet radio player, and Google search box.
The Maemo 5 UI is slightly different: The menu bar and info area are consolidated to the top of the display, and the four desktops can be customized with shortcuts and widgets.
At the Mobile World Congress in February 2010, it was announced that the Maemo project would be merging with Moblin to create the MeeGo mobile software platform.

webOS

Palm webOS is Palm's flagship mobile operating system running on the Linux kernel.
The Palm Pre smartphone was the first device to launch with webOS, and both were introduced to the public at the Consumer Electronics Show in Las Vegas on January 8, 2009 (2009-01-08). The Palm Pre and webOS were released on June 6, 2009 (2009-06-06). The second device to use the operating system, the Palm Pixi, was released on November 15, 2009. The webOS features significant online social network and Web 2.0 integration.

webOS's graphical user interface is designed for use on devices with touchscreens. It includes a suite of applications for personal information management and makes use of a number of web technologies such as HTML 5, JavaScript, and CSS.Palm claims that the design around these existing technologies was intended to spare developers from learning a new programming language.The Palm Pre, released on June 6, 2009, is the first device to run this platform. Devices currently running webOS include the Palm Pre and Palm Pixi on Sprint, and the "Plus" versions that run on Verizon Wireless and AT&T.

Windows Mobile

Windows Mobile  is a mobile operating system developed by Microsoft for use in smartphones and mobile devices. The current version is called "Windows Mobile 6.5". It is based on the Windows CE 5.2 kernel, and features a suite of basic applications developed using the Microsoft Windows API. It is designed to be somewhat similar to desktop versions of Windows, feature-wise and aesthetically. Additionally, third-party software development is available for Windows Mobile, and software can be purchased via the Windows Marketplace for Mobile.
Originally appearing as the Pocket PC 2000 operating system, most Windows Mobile devices come with a stylus pen, which is used to enter commands by tapping it on the screen. Microsoft announced a completely new phone platform, Windows Phone 7, at the Mobile World Congress in Barcelona on February 15, 2010. Phones running Windows Mobile 6.x will not be upgradeable to version 7.

Symbian OS

Symbian OS is one of Nokia's mobile operating system for mobile devices and smartphones, with associated libraries, user interface, frameworks and reference implementations of common tools, originally developed by Symbian Ltd. It was a descendant of Psion's EPOC and runs exclusively on ARM processors, although an unreleased x86 port existed.
In 2008, the former Symbian Software Limited was acquired by Nokia and a new independent non-profit organisation called the Symbian Foundation was established. Symbian OS and its associated user interfaces S60, UIQ and MOAP(S) were contributed by their owners to the foundation with the objective of creating the Symbian platform as a royalty-free, open source software. The platform has been designated as the successor to Symbian OS, following the official launch of the Symbian Foundation in April 2009. The Symbian platform was officially made available as open source code in February 2010.

BlackBerry OS

BlackBerry OS is RIM's proprietary mobile operating system, developed for its BlackBerry line of smartphone handhelds. The operating system provides multitasking and supports specialized input devices that have been adopted by RIM 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 in conjunction 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 OTASL (over the air software loading) service.
Third-party developers can write software using the available BlackBerry API (application programming interface) classes, although applications that make use of certain functionality must be digitally signed.

iOS (Apple)

iOS (previously named iPhone OS) is Apple's mobile operating system developed originally for the iPhone, and later deployed on the iPod Touch and iPad as well. It is derived from Mac OS X, with which it shares the Darwin foundation, and is therefore a Unix-like operating system by nature. In iOS, there are four abstraction layers: the Core OS layer, the Core Services layer, the Media layer, and the Cocoa Touch layer. The operating system uses roughly 500 megabytes of the device's storage.

Android (operating system)

Android is Google's operating system for mobile devices based on ARM architecture.Technologically, Android includes middleware and key applications, and uses a modified version of the Linux kernel. It was initially developed by Android Inc., a firm later purchased by Google, and lately by the Open Handset Alliance. It allows developers to write managed code in the Java language, controlling the device via Google-developed Java libraries.
The Android operating system software stack consists of Java applications running on a Java based object oriented application framework on top of Java core libraries running on a Dalvik virtual machine featuring JIT compilation. Libraries written in C include the surface manager, OpenCore media framework, SQLite relational database management system, OpenGL ES 2.0 3D graphics API, WebKit layout engine, SGL graphics engine, SSL, and Bionic libc. The Android operating system consists of 12 million lines of code including 3 million lines of XML, 2.8 million lines of C, and 2.1 million lines of Java.

Binary Runtime Environment for Wireless

BREW (Binary Runtime Environment for Wireless) is an application development platform created by Qualcomm, originally for CDMA mobile phones, but GSM is now also supported.
As a software platform that can download and run small programs for playing games, sending messages, sharing photos,and the like, the main advantage of BREW platforms is that the application developers can easily port their applications between all Qualcomm devices. BREW acts between the application and the wireless device on-chip operating system in order to allow programmers to develop applications without needing to code for system interface or understand wireless applications.

Java Platform, Micro Edition

Java Platform, Micro Edition, or Java ME, is a Java platform designed for mobile devices and embedded systems. Target devices range from industrial controls to mobile phones (especially feature phones) and set-top boxes. Java ME was formerly known as Java 2 Platform, Micro Edition (J2ME).
Java ME was designed by Sun Microsystems, now a subsidiary of Oracle Corporation; the platform replaced a similar technology, PersonalJava. Originally developed under the Java Community Process as JSR 68, the different flavors of Java ME have evolved in separate JSRs. Sun provides a reference implementation of the specification, but has tended not to provide free binary implementations of its Java ME runtime environment for mobile devices, rather relying on third parties to provide their own.
As of 22 December 2006, the Java ME source code is licensed under the GNU General Public License, and is released under the project name phoneME.
As of 2008, all Java ME platforms are currently restricted to JRE 1.3 features and uses that version of the class file format (internally known as version 47.0). Should Sun ever declare a new round of Java ME configuration versions that support the later class file formats and language features, such as those corresponding JRE 1.5 or 1.6 (notably, generics), it will entail extra work on the part of all platform vendors to update their JREs.
Java ME devices implement a profile. The most common of these are the Mobile Information Device Profile aimed at mobile devices, such as cell phones, and the Personal Profile aimed at consumer products and embedded devices like set-top boxes and PDAs. Profiles are subsets of configurations, of which there are currently two: the Connected Limited Device Configuration (CLDC) and the Connected Device Configuration (CDC).

Feature phone

Feature phone is a term used to describe a low-end mobile phone that has less computing ability than a smartphone. They are sometimes referred to as "dumb phones", as they don't have all the connectivity of a smartphone.
Feature phones can often run simple applications based on Java ME or BREW. However, the feature phone has less advanced programming APIs and is unable to run native software specific to a smartphone platform.Some analysts have predicted that as the price of smartphones comes down, the smartphone may eventually eclipse the feature phone.

Smartphone

Smartphones run complete operating system software providing a platform for application developers. Smartphone may be thought of as a handheld computer integrated within a mobile telephone. Growth in demand for advanced mobile devices boasting powerful processors, abundant memory, larger screens and open operating systems has outpaced the rest of the mobile phone market for several years.

The first smartphone was called Simon; it was designed by IBM in 1992 and shown as a concept product that year at COMDEX, the computer industry trade show held in Las Vegas, Nevada. It was released to the public in 1993 and sold by BellSouth. Besides being a mobile phone, it also contained a calendar, address book, world clock, calculator, note pad, e-mail, send and receive fax, and games. It had no physical buttons to dial with. Instead customers used a touch-screen to select phone numbers with a finger or create facsimiles and memos with an optional stylus. Text was entered with a unique on-screen "predictive" keyboard. By today's standards, the Simon would be a fairly low-end product; however, its feature set at the time was incredibly advanced.

Operating systems that can be found on smartphones include Symbian (including S60 series), iOS, Palm WebOS, BlackBerry OS, Samsung bada phones running Linux, Binary Runtime Environment for Wireless, Windows Mobile, Android and Maemo. WebOS, Android and Maemo are built on top of Linux, and the iOS is derived from the BSD and NeXTSTEP operating systems, which all are related to Unix.

Mobile operating system

A mobile operating system, also known as a mobile OS, a mobile platform, or a handheld operating system, is the operating system that controls a mobile device—similar in principle to an operating system such as Mac OS, Linux or Windows that controls a desktop computer or laptop. However, they are currently somewhat simpler, and deal more with the wireless versions of broadband and local connectivity, mobile multimedia formats, and different input methods.

Operating systems that can be found on smartphones include Symbian OS, iPhone OS, RIM's BlackBerry, Windows Phone, Linux, Palm WebOS, Android and Maemo. Android, WebOS and Maemo are in turn built on top of Linux, and the iPhone OS is derived from the BSD and NeXTSTEP operating systems, which all are related to Unix.