Android is an operating system for mobile devices such as smartphones and tablet computers. It consists of a kernel based on the Linux kernel, with middleware, libraries and APIs written in C and application software running on an application framework which includes...
iOS is a mobile operating system developed by Apple Inc. and distributed exclusively for Apple hardware. It is the operating system that powers iPhone, iPod Touch, and formerly iPad.
Astian OS is an operating system that is based on the discontinued Firefox OS, development by Astian Foundation, thus allowing support for mobile devices, TV's, and other devices. Astian OS is completely free and open.
B2G is a community maintained open source operating system for smartphones, tablets, smart TVs and other connected devices. The project was started in 2011 and is based on the Linux kernel and Gecko rendering engine.This app doesn't have any features at the moment.Discontinued
The project is discontinued.See: https://developer.mozilla.org/en-US/docs/Archive/B2G_OS
QtMoko is debian distribution for Linux based SmartPhones, like Openmoko Freerunner and Goldelico's GTA04 phone. Phone and user interface is based on QT Extendeded formerly known as Qtopia..
The project seems to be no longer developed. Last version, v58, released in December 2013, can be still downloaded from SourceForge.