The “How-to-Make-a-Computer-Operating-System” ebook provides a comprehensive guide in 9 chapters for creating your own computer operating system using C and C++.
With over 20,000 stars and 3,500 forks, this project shows great potential for further development. The ebook is released under the Apache License 2.0, which is business-friendly, making it a good basis to start a business with this project or gain experience and recognition as a developer.
It’s master branch got its last commit a while back though, on 2015-10-29.