28 Major Mobile OS

Title	Image	Description
Android		A free and open source Linux based operating system for touchscreen mobile devices such as smartphones and tablet computers. Initially developed by Android, Inc., which Google backed financially and eventually bought.
iOS		Apple's proprietary operating system for iPhone, iPod Touch, iPad and Apple TV (2nd generation).
BlackBerry OS		A proprietary mobile operating system developed by BlackBerry Ltd. It is the predecessor of the BlackBerry 10 mobile operating system.
BlackBerry 10		Proprietary mobile operating system developed for BlackBerry smartphones and tablets.
BlackBerry PlayBook OS		An operating system based on the QNX Neutrino real-time operating system designed to run Adobe AIR and BlackBerry WebWorks applications. Also known as BlackBerry Tablet OS.
Windows Phone		Series of proprietary mobile operating systems developed by Microsoft. The successor to the Windows Mobile platform.
Windows RT		A variant of the Windows 8 operating system for mobile devices.
Windows Mobile		A family of mobile operating systems developed by Microsoft for smartphones and Pocket PCs. Windows Mobile is the predecessor of Windows Phone.
Bada		An operating system developed by Samsung Electronics, for mobile devices such as smartphones and tablet computers.
Symbian OS		A mobile operating system and computing platform designed for smartphones. It is currently maintained by Accenture, and was originally developed by Symbian Ltd.
Aliyun OS		A Linux distribution designed for smartphones, developed by AliCloud, a subsidiary of Chinese company Alibaba Group. Aliyun OS is also known as Yun OS.
Firefox OS		A Linux based open source operating system developed by Mozilla, for smartphones and tablet computers.
Ubuntu Touch		A mobile interface for Ubuntu developed by Canonical Ltd, designed primarily for touchscreen mobile devices such as smartphones and tablet computers.
Nokia Asha		A mobile operating system and computing platform designed for low-end borderline smartphones. It is the successor of Series 40.
Palm OS		A mobile operating system initially developed by Palm, Inc., for personal digital assistants (PDAs). Palm OS is also known as Garnet OS.
Series 40		Proprietary operating system from Nokia. Also known as S40 OS.
Sailfish OS		Linux based mobile operating system developed by Jolla in cooperation with the Mer project and supported by the Sailfish Alliance.
GridOS		GridOS was built by Fusion Garage, using open source code from the Android kernel. It is the operating system of the Grid 4 mobile phone and Grid 10 tablet.
Mer project		Mer is fork of MeeGo, and is an open, mobile-optimised, core distribution aimed at device manufacturers.
Brew		BREW stands for Binary Runtime Environment for Wireless. It is an application development platform created by Qualcomm, originally for CDMA (code division multiple access) mobile phones.
SHR		SHR stands for Stable Hybrid Release. It is a community-driven Linux distribution for smartphones which is based on OpenEmbedded and the FSO framework.
webOS		A mobile operating system based on a Linux kernel, and was initially developed by Palm, which was later acquired by Hewlett-Packard and then LG Electronics.
Tizen		An open source operating system for smartphones, tablets, in-vehicle infotainment (IVI) devices, and smart TVs.
DangerOS		A largely Java-based operating system for the Danger Hiptop line of smartphones.
LiMo 4		An open source, hardware-independent, Linux based mobile operating system for smartphone mobile devices. It is from The LiMo Foundation, a non-profit technology consortium organisation.
Maemo		A software platform (based on the Debian Linux distribution), for smartphones and tablets.
MeeGo		A Linux based free mobile operating system designed for hardware platforms such as netbooks, entry-level desktops, nettops, tablet computers, mobile computing and communications devices, in-vehicle infotainment devices, SmartTV / ConnectedTV, IPTV-boxes, smart phones, and other embedded systems.
Nucleus RTOS		A real-time operating system (RTOS) and toolset created by the Embedded Systems Division of Mentor Graphics, and is designed for embedded systems applications including consumer electronics, set-top boxes, cellular phones, and other portable and handheld devices.