Ace Operating System Project - An open source operating system for X86 architecture. It also contains documents, specifications explaning various hardwares.
Cottontail OS Development Library - Online library covering a plethora of OS development topics. Datasheets, tutorials, reference manuals and hardware programming information.
DXOS - Developed by Richard Hayden, also containing information on low-level systems and operating system programmming, forums.
Groovyweb: Operating system programming - An open source os written in Turbo C (for DOS/ windows) and nasm (Windows/Dos/Linux) as well as two exclusive tutorials on how to write an operating system.
High Flex Modular Operating System Journal - Follow the pre-design, brain-storming, development, post-design, and perfection of a modern 32-bit operating system for the intel x86 platforms.
JOSH - Operating Systems Development Tutorial - Tutorial on operating system development leading to the development of a real mode single tasking operating system developed in assembler.
KernelNewbies.org - Resources for programmers new to kernel hacking. Example code, FAQs, utilities for debugging modules.
LusitanOS - Yet another open source operating system, planned to be an OS entirely made by Portuguese people and built mainly as a way of self-lerning and research on operating systems development. [Open source]
Operating System Design Tutorials - A set of well-written design tutorials: tells you the whys as well as the hows. With examples for the x86 architecture.
Operating Systems and System Software - Contains sources of a minimal kernel, a new CPU scheduler for Linux, multithreading in Linux, systems software in DOS and collection of good reference material for OS lovers.
The Operating Systems Resource Center - Extensive information about booting, file systems, memory, architecture, and interfacing with other devices.
OS Development - Message board, OS development links, and the Operating System project web ring.
OS Development Directory - Links on different OS development related subjects such as theory, hardware, tutorials, tools and reference materials.
OSDEV Community - Attracts OS programmers across the Net in order to provide a common, user-friendly, working space. OS projects. Documentation, forum.
The OSKit Project - An open source set of libraries that can be used as building blocks for an operating system for x86. Includes documentation and publications.
Therx OS Development Library - A site containing archived documents relating to the programming of Operating Systems.
Tony Macs Programming Pages - Focuses on x86 programming and includes links to other good sites, including MenuetOS. Collectoin OS sreenshots.
Triada - Ukrainiann Operating System. OS sources, toolkit downloads. OS development related articles.
Triple Fault Club - Information on writing your own operating system, protected mode, and small independent OS projects with freely-available source code.
Tuomo Kortesmaa - Notes and example code for basic operating systems concepts, threads, sockets, and device drivers.
Write Your Own Operating System [FAQ] - The Hobbyist guide to writing your own operating system from the ground up, Question and Answer style on everything from PMode to filesystems to GCC and doing it in C++.
