Smartphones include a pair of mobile operating systems – the primary user-facing software system is supplemented by an additional low-level exclusive real-time operating system which runs the radio and camera as well as other hardware.
Operating systems can be classified into several categories, one of them being if they are open (have access to certain components that you can change at will) or closed source (Proprietary software give the right to utilize the software just under particular conditions, and limited from other uses, for example customization, sharing, analyzing, redistribution, etc).
Android is the most popular open source but other SO are: Tizen, Mer, Sailfish OS, Ubuntu Phone,Firefox OS and other little distributions.
Instead iOS is the most popular OS with Proprietary EULA ,other being: Windows Phone, BlackBerry OS, Bada, Asha with all the other operating systems from Nokia.
A few words about other operating systems, because everyone knows about android and ios or Windows and BlackBerry.
Bada was developed by Samsung until February 2012 when they moving development to Tizen instead.
Tizen is a development within the Linux Foundation, is governed by Technical Steering Group and made of Samsung with Intel. By 2014 was not launched any product based on this OS
but promises a lot and can be installed on smartphones, tablets, in-vehicle infotainment devices, smart TVs and cameras.
Firefox OS is being developed by Mozilla, the organization most famous for the Firefox net browser and is designed to be an open platform without the rules and constraints of current proprietary platforms. Firefox OS is created using HTML5.
Sailfish OS was created by a team of engineers who used Nokia MeeGo platform for developing the OS. Is impartial mobile OS that enables free competition and innovation, without predominant regulation by just one player. First phone was launched at the end of November 2013 by Jolla and is compatible with 100 000 Android applications.
Ubuntu Touch is a mobile version of Uuntu OS and his simpleness and style are going to be on your mobile phone. Being supported by Canonical, Ubuntu for phone is wished to contest with major proprietary platforms.
I would not want to be forgotten the former king, the first Symbian the first modern mobile OS on a smartphone with the launch of the Ericsson R380. It was the most popular smartphone OS on a worldwide average until the beginning of 2011. It’s the result of an alliance made in 1998 between Ericsson, Nokia, Motorola, and Psion to take advantage of the convergence between PDAs and mobiles.
In 2006, Symbian had 73% of the smartphone market and 100 million smartphone running the OS was shipped, that given the smartphone market was not as big as now.
Nokia identify with Symbian and in 2008 was acquired by the company completely both share the same moments of glory and the same period for declining, symbian si now on 2.3% of the mobile phones and Nokia mobile division was sold in september 2013 to Microsoft.
The Nokia 808 PureView is officially the last and final Symbian (Nokia Belle) smartphone.
At the final an opinion about Symbian OS: most granted it’s less smooth and user friendly compared to other OSes, but Belle FP1/2 is very stable and feature rich (multi-tasking, customisable, file manager, Nokia Drive and offline maps, screensaver always on clock etc), almost like Android without the high gloss and ads.