Nov 10, · Today we have made Firefox OS available worldwide. We are also making an early, experimental build of the OS — Firefox OS Developer Preview — available for developers to download on Android devices. This latest version of Firefox OS delivers exciting features including: To . Jan 22, · Mozilla today unveiled two new developer preview phones that feature the browser maker's Firefox OS. The phones - dubbed Keon and Peak - are being developed via Spanish phone maker GeeksPhone in. Perhaps a better question: for someone wanting a phone with Firefox OS , what would be the path of least resistance? Examples - phone has Firefox OS pre-installed - phone had Firefox OS pre-installed, but has or nightly builds available If something is available like this, then I . Firefox OS is a discontinued open-source operating system – made for . Mozilla announced at a press conference before the start of Mobile World Congress in Barcelona that the first wave of Firefox OS. There are a number of emerging Web platform standards and device APIs crucial to Firefox OS app development and to Open Web Apps. This. As we've already mentioned Firefox OS apps are based on web web app development topics specific to creating apps that are installable on Firefox writing install functionality, permissions for using device APIs, and more.