While I like the idea of starting a hobby OS, but the most despairing thing about it that to be useful it would always have to implement 'legacy' interfaces of other OSes. That is, it cannot stand on its own and create a new ecosystem, instead it has to interface to the world and implement TCP, POSIX, know formats widely used files and such.

You end up with an OS kernel that talks Linux/Win32 and takes on a lot of compat code, protocols, and other paradigms.

I wonder what a hobby OS would have looked like it if it assumed nothing, that is, as a thought experiment, as if aliens on another planet invented computing and started writing OSes from scratch. Imagine we discover software from another planet that would not even work with 8-bit bytes, for instance.

Impressive! I like the goal of making a hobby OS viable as a daily driver.

I've been working on my own hobby OS for half a decade. It does a lot less, but it has helped me realize that we can remove much of the complexity of a generic mainstream OS while still meeting our personal computing needs. I know I'm just poorly reinventing something between DOS and Unix/Plan 9 in an extremely limited fashion, but it's absolutely perfect for experimentation!

I wish people would start with a "rom format" for windows games. There's so many old games and no standardized way to run them.