Re:Plan 9 released under GPLv2
by yxhuvud on Thursday February 13, 2014 @12:46PM
(#7232800)
They also backport a lot of it upstream to FreeBSD. It is not a black and white question.
[ Parent
| on HN ]
If one go by market share, the code sent back upstream are worth far less than 1% of Os X.