SerenityOS is a from-scratch Unix-like operating system started by Andreas Kling. Its userland, C++ standard library, kernel and GUI toolkit are all written in-house, producing a system that deliberately echoes the aesthetics of late-1990s productivity software while offering modern power-user accessibility.

Key Features

• Everything written from scratch — kernel, LibC, libGUI, applications and libraries are original code, not a Linux distribution
• Custom desktop environment — a window manager, terminal, text editor and utilities in a 1990s-inspired style
• Home of the Ladybird browser — SerenityOS’s in-house web engine grew into its own independent project
• Built-in developer tooling — Hack Studio IDE and a full C++ toolchain
• Active contributor community — extensive documentation and a public bug bounty history

Why Use It

SerenityOS is one of the few operating systems built end-to-end from nothing, which makes it exceptionally valuable for learning and teaching operating system development — every layer is readable, documented and modifiable. For enthusiasts it is also a genuinely usable experimental desktop with a distinctive, cohesive design.

Use Cases

• Operating system development — study or contribute to a complete from-scratch system
• Computer science education — kernel, filesystem, GUI and browser internals in one codebase
• Experimental desktop — run it in a virtual machine for a retro-flavoured Unix experience

Platform

x86-64 is the primary target, with experimental ports to other architectures. Runs on bare metal and in virtual machines.

Licence

Free and open source — BSD 2-Clause Licence.

Website

serenityos.org