OpenBSD has been expanding the fork+exec model throughout its source tree, since the OpenSSH preauth work done by Damien Miller, many more followed. The list in

OpenBSD has been expanding the fork+exec model throughout its source tree, since the OpenSSH preauth work done by Damien Miller, many more followed. The list includes bgpd/ldpd/eigrpd/smtpd/relayd/ntpd/httpd/snmpd/ldapd and most recently slaacd & vmd. A few remain but are being converted as they are discovered.