In parallel BSD has had its own continuing revolution, around 1990 Free BSD was created as the source code successor to the original BSD code before that it was known as 386BSD.
1994 Linux 1.0 release
Mid 90s FreeBSD bore two spin-offs (known as source code forks) [this happens when certain people decide to take OS development in different direction]. NetBSD and Open BSD all three derivatives are currently maintained today.
Net BSD is aimed at broad platform support and is widespread in the scientific community;
OpenBSD is most popular on PC and is used and focuses on security and is very popular as a firewall platform
There are commercial derivatives of BSD the most popular is BSDi