Originally published at: https://www.cyberciti.biz/tips/openbsd-add-package-howto.html
Just like FreeBSD, OpenBSD comes with pkg_add command. It is used to install a binary or upgrade packages from HTTP or FTP mirror over the internet. If you have purchased OpenBSD DVD/CD, you can install packages using CD itself. The pkg_add command used to update existing packages too. Please note that you can no longer purchase OpenBSD DVD.