18 Mar
1999
18 Mar
'99
7:21 p.m.
However, it is believed that they started out with NetBSD
It started with the Net-2 stack, was upgraded to the 4.4-Lite-2 stack in the 4.0 release, and had bits of other stacks, including some 64-bit-cleansing from the NetBSD stack, added over time, as well as various other changes.
It's still very much a BSD-derived stack.