Aside from base Linux/Debian/etc, I would argue that there are no other personal server operating system companies. If you are referring to the other plug and play node solutions, EmbassyOS is the only one I would really call an "operating system". I feel like that concept requires a minimum degree of functionality and control to the user, which none of them provide. They are more like "bundles of services" that you can view in a GUI. Almost ever action beyond simply installing ans starting a service requires SSH and command line usage. Only EmbassyOS affords users the ability to MANAGE their server over time, essentially turning an average person into a systems administrator or dev ops engineer.