While Fuchsia is open source, it was barred from contributions by outside developers, until now. Google has now expanded the open source model to allow anyone to contribute to the development of the Fuchsia OS project.
Fuchsia is rather a digression, as all Google's operation systems are based on the Linux kernel, including Android and Chrome OS. And Fuchsia is based on Magenta kernel, and specifically for embedded hardware, especially embedded devices like car dashboards or GPS units, as the Linux kernel impacts performance which could cause some problems.
Fuchsia OS - Google's new Operating System outside the Linux kernel
Fuchsia OS is based on Magenta kernel, and designed to work across a wide range of devices—from small "embedded devices" all the way up to mobile devices and even laptops and desktops.
Google maintains that Fuchsia OS is a long-term project aimed at creating a general-purpose open source operating system with its own kernel with priorities for security and performance. And currently, it supports a limited number of x64-based hardware, which can also be tested using Fuchsia’s emulator.
It uses Google's own Material Design-friendly Flutter user-interface framework, as well as Dart as the primary programming language.
Fuchsia OS Development Going Public
Fuchsia was developed exclusively by the Fuchsia team, and Google have been developing Fuchsia in the open, in its git repository for the last four years.
Now, Google wants to allow outside developers to become members of the project to submit security patches or to become committers with full write access. If you're a developer and want to contribute to Fuchsia OS, you can download the source code, and get started with contributing to Fuchsia OS, from the official site.