Android is a Linux kernel based OS developed by Google. So far it has been most popular OS and has most of the user base in the market mainly because it is open source. Apart from Google’s Android there are more OS which are based on the Android Open Source Project(AOSP). Major AOSPs are Amazon’s Fire OS, Cyanogen Mod and Xiaomi’s MIUI.
iOS is built on the open source Darwin core OS. It is a close source and proprietary software developed by Apple Inc. iOS was derived from OSX which was also developed by Apple intended for desktop PCs. It has the second most largest share in the market. Apart from iPhone, iOS is also used in iPods, iPad and Apple TV. It was the first OS to introduce voice assistant, SIRI in its smart phones. With it’s new feature continuity user can switch to any other iOS device and continue work from where he or she left it. It also features iCloud which is Apple's cloud service to store pictures and other files on it’s cloud.
Windows is a close source proprietary OS developed by Microsoft. It’s authentic design is made using METRO and has clean and modern looks. It has the third largest share in the market. It has full integration of Microsofts’s services such as Office, OneDrive, Xbox and Bing. It also integrates third party services such as Facebook, Twitter etc. Cortana mobile assistant is a key feature in Windows Phones. Microsoft also provides interface customization to match everyones personal taste.
BlackBerry OS is a closed source and proprietary OS developed by Black Berry. It is based on QNX OS. BlackBerry manufactures all its smart phones and tablets by itself. It features an enhanced keyboard which can be adjusted according to fingers and it also features flow and peek which allows user to switch between apps without pressing back button. BlackBerry also provides a separate messaging app, BBM which is one of the salient features of Black Berry OS.
Firefox OS is developed by Mozilla. It is an open source Operating System and is based on the central theme of “Web is the platform”. The search in Firefox is developed such that it gives a combined result of data from websites and applications installed on device.
Sailfish OS is from Jolla. It is partly open source and adopts GPL (core and middleware), however the user interface is closed source. After Nokia failed in 2011 with the MeeGo project most of the MeeGo team left Nokia and established Jolla as a company to use MeeGo and MER business opportunities. In 2012 Linux Sailfish OS based on MeeGo and using MER core distribution has been launched for public use. The first device, Jolla (a mobile phone) was unveiled on 20 May 2013.
Tizen is hosted by the Linux Foundation and gets support from the Tizen Association, guided by a Technical Steering Group comprising of Intel and Samsung. Tizen is an operating system for devices including smartphones, tablets, in-vehicle infotainment (IVI) devices, and smart TVs. It is an open source system(However the SDK was closed source and proprietary) that aims to offer a consistent user experience across devices. Tizen's main components are the Linux kernel and the WebKit runtime. According to Intel, Tizen “combines the best of LiMo and MeeGo." HTML5 apps are emphasized and Tizen will be targeted at a variety of platforms such as handsets, touch pc, smart TVs and in-vehicle entertainment. On May 17, 2013, Tizen released version 2.1, code-named Nectarine.
Ubuntu Touch (also known as Ubuntu Phone) is a mobile version of the Ubuntu operating system developed by Canonical UK Ltd and the Ubuntu Community. It is designed primarily for touchscreen mobile devices such as smartphones and tablet computers. Ubuntu’s scopes give you related content on one screen, instead of hiding it behind different apps. So everything you look for in life is now right at your fingertips.