Unix was only rebranded in the early 80s at the exact time DOS was released. However, Unix's unintended "re-branding" was at its birth: due to its portability &

Unix was only rebranded in the early 80s at the exact time DOS was released. However, Unix's unintended "re-branding" was at its birth: due to its portability & availability in source, every installation was almost a "port".