Google is developing a brand new operating system that's quite a departure from its previous offerings. The open source project was discovered on GitHub with the description “Pink + Purple == Fuchsia (a new Operating System).”
Unlike Google’s other OSes such as Android and Chrome OS, Fuchsia isn’t based on Linux; instead, it uses the new Magenta Kernel, which is designed to power Internet of Things devices and compete against commercial embedded operating systems such as FreeRTOS and ThreadX, according to Android Police. However, Magenta is easily scalable so it can work on things like smartphones and desktop/laptop PCs.
Fuchsia supports both 32-bit and 64-bit ARM CPUs, 64-bit PCs, user modes, and a capability-based security model. It uses Google’s in-house Dart programming language and the Flutter user interface framework, suggesting that Fuchsia is built with Material Design in mind.
Google has yet to announce Fuchsia, but 9to5Google reports that two engineers from the company confirmed a couple of details: Google had decided to build Fuchsia open source from the beginning, which is why it's publicly visible; and it will eventually be officially announced and documented, but no there’s no timeframe for when this might happen.
Until Google reveals more, whatever plans it has for Fuchsia remain unknown. Its usage may not extend beyond IoT devices, or it could ultimately become the replacement for Android and Chrome OS. You can have a look at it yourself over on Github.