Comment by pecg

FreeBSD's kernel offers better performance (on the server) compared to Linux, and the licensing model makes it more attractive to some industries. Whatsapp (server side), Netflix, and the internals of PS3/4 all use FreeBSD code. OpenBSD is actively used in networks, as a firewall (where iptables from Linux is a mess) and other security oriented aspects where stability is also crucial. Linux is popular because it became available to users first than the others back in the 90s, OpenBSD's contributors, on the contrary, are comfortable on not implementing overengineered "features" with the sole purpose on keeping the source clean, stable, and with as less bugs as possible, as a UNIX system should be.