SerenityOS

SerenityOS is a free and open source desktop operating system. It features a preemptive kernel, currently supports x86-64, ARM, and RISC-V based computers, and hosts multiple complex applications including its own web browser and integrated development environment (IDE). Development started in 2018—initially as a one-man project of Swedish programmer Andreas Kling—and is now developed by a community of hobbyists. The project is hosted at GitHub and is described as being not catered to "non-technical users". Provided by Wikipedia