As a side point, I believe David Cutler, the venerable OS engineer who programmed and designed three OSes, did not like Unix very much back in the 90s. I wonder what was the reason, and did he change his mind later?
Era-appropriate joking aside: There's no actual evidence that Cutler held the views on Unix, or even on DEC's Eunice, that have been ascribed to xem from anecdotes by Armando Stettner and edits to Wikipedia and writing by G. Pascal Zachary. I and others went into more detail on this years ago: https://news.ycombinator.com/item?id=22814012
https://retrocomputing.stackexchange.com/questions/14150/how...
[Cutler] expressed his low opinion of the Unix process input/output model by reciting "Get a byte, get a byte, get a byte byte byte" to the tune of the finale of Rossini's William Tell Overture.
- A well-defined HAL for portability
- An object manager for unified resource lifecycle and governance
- Asynchronous I/O by default
- User-facing APIs bundled into independent “personalities” and decoupled from the kernel
The only real black mark I’m aware of is the move of the graphics subsystem into the kernel for performance, which I don’t think was Cutler’s idea.