There are 90 repositories under osdev topic.
Learning operating system development using Linux kernel and Raspberry Pi
A free Windows-compatible Operating System
A completely-from-scratch hobby operating system: bootloader, kernel, drivers, C library, and userspace including a composited graphical UI, dynamic linker, syntax-highlighting text editor, network stack, etc.
A BSD-based OS project that aims to provide an experience like and some compatibility with macOS (formerly known as airyxOS)
A proof-of-concept microkernel that implements a WebAssembly "usermode" that runs in Ring 0.
A kernel designed to run one and only one application in a virtualized environment
🥑 The delightful operating system.
Unikraft is an automated system for building specialized OSes known as unikernels. Unikraft can be configured to be POSIX-compliant. (Core repository)
A list of operating systems and stuff
🏢 An operating system inspired by brutalist design that combines the ideals of UNIX from the 1970s with modern technology and engineering
libhermit-rs: A Rust-based library operating system
a little 64bit operating system written in c++ with smp support
RustyHermit - A Rust-based, lightweight unikernel
Gramado Kernel 1.5 64bit | ( bootloader + kernel + posix commands )
An operating system written in D
Writing & Making Operating System and Kernel parts so simple like Hello World Programs, Starting from writing Bootloaders, Hello World Kernel, GDT, IDT, Terminal, Keyboard/Mouse, Memory Manager, HDD ATA R/W, VGA/VESA Graphics
A simple, clean code, multi-tasking operating system written in pure assembly language for 64-bit processors from the AMD64 family.
An operating system written in C
A hobby operating system developed from scratch
Yet another hobby x86 UNIX-like operating system written in C and C++. Features a dynamically linked userspace, an in-house c standard library, and more! And yes, it runs DOOM.
Microkernel and userspace written in Rust exploring modern ideas