1. BADA OS: Bada Os is discontinued Mobile operating system launched in June 2010 by SAMSUNG Electronics,written in C++. It is based on Open Source model and on Linux Kernel like android. It had a App market Named Samsung Apps like in Android had Play store. Unfortunately this OS not got popular as much as android & discontinued in 2013 :(
2. Tizen OS: Tizen is another Mobile operating system for Smartphones and tablet launched in 2013 by SAMSUNG Electronics. It was written in HTML5, C and C++, based on LINUX kernel type Monolithic kernel.It is and open source model based like android. The first Tizen tablet was launched by Systena in October 2013 a part of a development kit exclusive to Japan and it was a 10-inch quad-core ARM with 1920×1200 resolution.
3. Firefox OS: Firefox OS is discontinued smartphone operating system as well launched by Mozilla and external contributors in 2013. It was also an open source platform and Kernel type Monolithic (Linux). It was written in HTML5, CSS, JavaScript and C++. Unfortunately On December 8, 2015, Mozilla announced the discontinuation of Firefox OS and it would not be sale.
4. Symbian: Earlier It was launched by Symbian ltd in 1998, After that Nokia took over this platform in 2011. It was written in c++ and belongs to RTOS family. It was a Closed Sourced Operating System. It was very popular mobile OS across the world. But since Android OS launched, Symbian got a tough competition and in last it was discontinued in 2013 by Nokia.
2. Tizen OS: Tizen is another Mobile operating system for Smartphones and tablet launched in 2013 by SAMSUNG Electronics. It was written in HTML5, C and C++, based on LINUX kernel type Monolithic kernel.It is and open source model based like android. The first Tizen tablet was launched by Systena in October 2013 a part of a development kit exclusive to Japan and it was a 10-inch quad-core ARM with 1920×1200 resolution.
3. Firefox OS: Firefox OS is discontinued smartphone operating system as well launched by Mozilla and external contributors in 2013. It was also an open source platform and Kernel type Monolithic (Linux). It was written in HTML5, CSS, JavaScript and C++. Unfortunately On December 8, 2015, Mozilla announced the discontinuation of Firefox OS and it would not be sale.
4. Symbian: Earlier It was launched by Symbian ltd in 1998, After that Nokia took over this platform in 2011. It was written in c++ and belongs to RTOS family. It was a Closed Sourced Operating System. It was very popular mobile OS across the world. But since Android OS launched, Symbian got a tough competition and in last it was discontinued in 2013 by Nokia.