Don't forget tmux, cwm, openbgpd, and openntp. The OpenBSD guys consistently make very high quality tools.
cwm is a diamond in the rough for sure. Doesn't look like much but it's so easy to configure and use.
I absolutely love cwm. Best floating window manager, hands down.
Especially OpenSSH...
"OpenBSD Innovations": https://www.openbsd.org/innovations.html
Armorlogic, Calyptix Security, GeNUA, RTMX, and .vantronix make network appliances based on the complete OS.