Unlike Linux, MacOS, and Windows, which are all completely finished.
But also: most of the work of an OS is supporting a variety of hardware. That's not very intellectually interesting work. Hardware is usually hacky, and since was only ever tested against the manufacturer's driver code, the only way to use it reliably is to slavishly follow their usage.
But also: most of the work of an OS is supporting a variety of hardware. That's not very intellectually interesting work. Hardware is usually hacky, and since was only ever tested against the manufacturer's driver code, the only way to use it reliably is to slavishly follow their usage.