There are quite a few operating systems which have moved beyond the simple hobby operating system stage, onto a more lasting plane of existen.......
Five Advanced Operating Systems That Have Transcended from Hobby Projects to Long-Term Investments
1. AROS: The Operating System that Outranks the Rest
2. ReactOS: Redefining Longevity in the OS World
3. SkyOS: The Future-Forward IDE for High-End Developers
4. Syllable: A Rising Star with VLC and MPlayer Ports
5. From Hobby Projects to Revolutionary OS: The Evolution of Haiku, Syllable, and More