386BSD the predecessor of Net/Free/OpenBSD was published under a BSD license in 1992. 6 months after Linus posted his kernel sources on usenet. It was free and

386BSD the predecessor of Net/Free/OpenBSD was published under a BSD license in 1992. 6 months after Linus posted his kernel sources on usenet. It was free and open source and no later than the "free" BSDs that are still available today. I'd say that is a reason why it is successful. Edit: "free" in quotatio marks to not confuse with FreeBSD.