reactos/reactos

ReactOS is an open source operating system aiming for compatibility with Windows applications and drivers

Runs Windows apps as Linux desktop programs with system integration
winapps-org/winapps
Ubuntu-based Linux OS with a Windows-like interface, easy for new users
Anduin2017/AnduinOS
Linux OS for running Home Assistant on Raspberry Pi, NUC, and more
home-assistant/operating-system
Open-source platform with interactive coding projects and certifications on freeCodeCamp
freeCodeCamp/freeCodeCamp
90s-style Unix-like OS for modern PCs
SerenityOS/serenity
Low-code platform for building internal tools and custom apps
openblocks-dev/openblocks
List of open-source alternatives to popular SaaS products
RunaCapital/awesome-oss-alternatives
experimental Linux distro built from scratch in Go
itsManjeet/rlxos
open source platform for launching and discovering new products
Drdruide/Open-Launch
Windows ARM in Docker containers for devices like Raspberry Pi
dockur/windows-arm