Software developed or maintained by the OpenBSD project

Started from scratch as parts of OpenBSD

OpenBGPD including bgpd(8) and bgpctl(8): Written and maintained by Henning Brauer and Claudio Jeker. Imported December 17, 2003 and first released with OpenBSD 3.5.
OpenNTPD including ntpd(8) and ntpctl(8): Written and maintained by Henning Brauer. Imported May 31, 2004 and first released with OpenBSD 3.6. Portable version maintained by Brent Cook.
relayd and httpd:
relayd(8) with relayctl(8): Started by Pierre-Yves Ritschard and Reyk Floeter. Imported December 16, 2006 and first released with OpenBSD 4.1. Now maintained by Reyk Floeter and Sebastian Benoit.
httpd(8): Started by Reyk Floeter. Imported July 12, 2014 and first released with OpenBSD 5.6. Maintained by Reyk Floeter and Florian Obser.
OpenSMTPD including smtpd(8), smtpctl(8), makemap(8): Started by Gilles Chehade. Imported November 1, 2008 and first released with OpenBSD 4.6. Now maintained by Gilles Chehade and Eric Faurot.
OpenIKED including iked(8) and ikectl(8): Started by Reyk Floeter. Imported June 3, 2010 and first released with OpenBSD 4.8. Now maintained by Reyk Floeter and Mike Belopuhov.

Started as OpenBSD forks of non-OpenBSD code

OpenSSH including ssh(1), scp(1), sftp(1), ssh-add(1), ssh-agent(1), ssh-keygen(1), sshd(8), sftp-server(8): Started by Aaron Campbell, Bob Beck, Dug Song, Markus Friedl, Niels Provos, and Theo de Raadt as a fork of SSH 1.2.12 by Tatu Ylonen. Imported September 26, 1999 and first released with OpenBSD 2.6. Now maintained by Markus Friedl, Damien Miller, Darren Tucker, and Theo de Raadt.
LibreSSL: Started by Ted Unangst, Bob Beck, Joel Sing, Miod Vallat, Philip Guenther, and Theo de Raadt in April 2014, first released with OpenBSD 5.6. Portable version maintained by Brent Cook.

Started outside OpenBSD, now maintained as part of OpenBSD

tmux, tmux(1): Started in 2007 and maintained by Nicholas Marriott. Imported June 1, 2009, first released with OpenBSD 4.6.
mandoc including mandoc(1), man(1), apropos(1), makewhatis(8), man.cgi(8): Started by Kristaps Dzonsons in November 2008. Imported April 6, 2009, first released with OpenBSD 4.8. Now maintained by Ingo Schwarze.

Invented in OpenBSD

Privilege separation: First implemented by Niels Provos and Markus Friedl in OpenSSH in March 2002, released with OpenBSD 3.2. The concept is now used in many programs.
W^X: First used for sparc, sparc64, alpha, and hppa in OpenBSD 3.3. Today, most architectures implement it.
ASLR: OpenBSD 3.4 was the first widely used operating system to provide it by default.
gcc-local(1) __attribute__((__bounded__)) static analysis annotation and checking mechanism: Started by Anil Madhavapeddy on June 26, 2003 and ported to GCC 4 by Nicholas Marriott. First released with OpenBSD 3.4.
malloc(3) randomization: Implemented by Otto Moerbeek for OpenBSD 4.4.
Static-PIE: Position-independent static binaries for /bin, /sbin and ramdisks. First released with OpenBSD 5.7.

Early adoption in OpenBSD

ipsec(4): Started by John Ioannidis, Angelos D. Keromytis, Niels Provos, and Niklas Hallqvist, imported February 20, 1997. OpenBSD was the first free operating system to provide an IPSec stack.
Stack protector: Developed since 2001 as "propolice" by Hiroaki Etoh. Integrated, and implemented for additional hardware platforms, by Miod Vallat and Theo de Raadt. OpenBSD 3.3 was the first operating system to enable it systemwide by default.
PIE: OpenBSD 5.3 was the first widely used operating system to enable it globally by default, on seven hardware platforms.

Started from scratch

AnonCVS: Designed and implemented by Chuck Cranor and Theo de Raadt in 1995 (paper, slides)
aucat(1): Started by Kenneth Stailey. Imported January 2, 1997 and first released with OpenBSD 2.1. Now maintained by Alexandre Ratchov.
pf(4), pfctl(8), pflogd(8), authpf(8), ftp-proxy(8): Started by Daniel Hartmeier as a replacement for the non-free ipf by Darren Reed. Imported June 24, 2001 and first released with OpenBSD 3.0. Now maintained by Henning Brauer.
systrace(4), systrace(1): Started by Niels Provos. Imported June 4, 2002 and first released with OpenBSD 3.2.
spamd(8): Started by Theo de Raadt. Imported December 21, 2002 and first released with OpenBSD 3.3. Now maintained by Bob Beck.
dc(1): Written and maintained by Otto Moerbeek. Imported September 19, 2003 and first released with OpenBSD 3.5.
bc(1): Written and maintained by Otto Moerbeek. Imported September 25, 2003 and first released with OpenBSD 3.5.
sensorsd(8): Started by Henning Brauer. Imported September 24, 2003 and first released with OpenBSD 3.5.
pkg_add(1): Written and maintained by Marc Espie. Imported October 16, 2003 and first released with OpenBSD 3.5.
carp(4): Written by Mickey Shalayeff, Markus Friedl, Marco Pfatschbacher, and Ryan McBride. Imported October 17, 2003 and first released with OpenBSD 3.5.
ifstated(8): Started by Marco Pfatschbacher and Ryan McBride. Imported January 23, 2004 and first released with OpenBSD 3.8.
hotplugd(8): Started by Alexander Yurchenko. Imported May 30, 2004 and first released with OpenBSD 3.6.
dpb(1): Started by Nikolay Sturm on August 10, 2004; first available for OpenBSD 3.6. Rewritten and maintained by Marc Espie since August 20, 2010.
ospfd(8), ospfctl(8): Started by Esben Norby and Claudio Jeker. Imported January 28, 2005 and first released with OpenBSD 3.7.
bioctl(8): Started by Marco Peereboom. Imported March 29, 2005 and first released with OpenBSD 3.8.
hostapd(8): Written and maintained by Reyk Floeter. Imported May 26, 2005 and first released with OpenBSD 3.8.
watchdogd(8): Started by Marc Balmer. Imported August 8, 2005 and first released with OpenBSD 3.8.
sdiff(1): Written by Ray Lai. Imported December 27, 2005 and first released with OpenBSD 3.9.
dvmrpd(8), dvmrpctl(8): Started by Esben Norby. Imported June 1, 2006 and first released with OpenBSD 4.0.
ripd(8), ripctl(8): Started by Michele Marchetto. Imported October 18, 2006 and first released with OpenBSD 4.1.
pkg-config(1): Started by Chris Kuethe and Marc Espie. Imported November 27, 2006 and first released with OpenBSD 4.1. Now maintained by Jasper Lievisse Adriaanse.
ospf6d(8), ospf6ctl(8): Started by Esben Norby and Claudio Jeker. Imported October 8, 2007 and first released with OpenBSD 4.2.
libtool(1): Written by Steven Mestdagh and Marc Espie. Imported October 28, 2007 and first available for OpenBSD 4.3. Now maintained by Marc Espie, Jasper Lievisse Adriaanse, and Antoine Jacoutot.
snmpd(8), snmpctl(8): Started by Reyk Floeter. Imported December 5, 2007 and first released with OpenBSD 4.3. Maintained by Reyk Floeter and Bret Lambert.
ypldap(8): Started by Pierre-Yves Ritschard. Imported June 26, 2008 and first released with OpenBSD 4.4.
ldpd(8), ldpctl(8): Started by Michele Marchetto. Imported June 1, 2009 and first released with OpenBSD 4.6. Now maintained by Claudio Jeker.
ldapd(8), ldapctl(8): Written by Martin Hedenfalk. Imported May 31, 2010 and first released with OpenBSD 4.8.
iscsid(8), iscsictl(8): Written and maintained by Claudio Jeker. Imported September 24, 2010 and first released with OpenBSD 4.9.
rc.d(8), rc.subr(8): Written and maintained by Robert Nagy and Antoine Jacoutot. Imported October 26, 2010 and first released with OpenBSD 4.9.
tftpd(8): Written and maintained by David Gwynne. Imported March 2, 2012 and first released with OpenBSD 5.2.
cu(1): Written and maintained by Nicholas Marriott. Imported July 10, 2012 and first released with OpenBSD 5.4.
ldomd(8), ldomctl(8): Written and maintained by Mark Kettenis. Imported October 26, 2012 and first released with OpenBSD 5.3.
sndiod(1): Written and maintained by Alexandre Ratchov. Imported November 23, 2012 and first released with OpenBSD 5.3.
identd(8): Written and maintained by David Gwynne. Imported March 18, 2013 and first released with OpenBSD 5.4.
slowcgi(8): Written and maintained by Florian Obser. Imported May 23, 2013 and first released with OpenBSD 5.4.
signify(1): Written and maintained by Ted Unangst. Imported December 31, 2013 and first released with OpenBSD 5.5.
htpasswd(1): Written and maintained by Florian Obser. Imported March 17, 2014 and first released with OpenBSD 5.6.
rcctl(8): Written and maintained by Antoine Jacoutot. Imported August 19, 2014 and first released with OpenBSD 5.7.
file(1): Rewritten from scratch and maintained by Nicholas Marriott. Imported April 24, 2015 and first released with OpenBSD 5.8.
doas(1): Written and maintained by Ted Unangst. Imported July 16, 2015 and first released with OpenBSD 5.8.
radiusd(8): Written and maintained by YASUOKA Masahiko. Imported July 21, 2015 and first released with OpenBSD 5.8.
rebound(8): Written and maintained by Ted Unangst. Imported October 15, 2015 and first released with OpenBSD 5.9.

Started as OpenBSD forks of non-OpenBSD code

m4(1): Originally implemented by Ozan Yigit and Richard A. O'Keefe for 4.3BSD-Reno. Considerably extended and maintained by Marc Espie since 1999.
sysmerge(8): Written and maintained by Antoine Jacoutot, originally forked from mergemaster by Douglas Barton. Imported April 22, 2008, first released with OpenBSD 4.4.

Started outside OpenBSD, now maintained as part of OpenBSD

ypbind(8), ypset(8), ypcat(1), ypmatch(1), ypwhich(1): Started by Theo de Raadt. Imported April 26, 1993 and first released with NetBSD 0.9.
ypserv(8): Started by Mats O. Jansson in 1994. Imported October 23, 1995 and first released with OpenBSD 2.0.
mopd(8): Started by Mats O. Jansson in 1993. Imported September 21, 1996 and first released with OpenBSD 2.0.
mg(1): Started by Dave Conroy in November 1986. Imported February 25, 2000 and first released with OpenBSD 2.7. Now maintained by Mark Lumsden.
dhclient(8): Started by Ted Lemon and Elliot Poger in 1996. Imported January 18, 2004 and first released with OpenBSD 3.5. Reworked by Henning Brauer. Now maintained by Kenneth Westerback.
dhcpd(8): Started by Ted Lemon in 1995. Imported April 13, 2004 and first released with OpenBSD 3.6. Reworked by Henning Brauer. Now maintained by Kenneth Westerback.
cwm(1): Started by Marius Aamodt Eriksen. Imported April 27, 2007 and first released with OpenBSD 4.2. Now maintained by Okan Demirmen.
npppd(8), npppctl(8): Started by Internet Initiative Japan Inc. Imported January 11, 2010, first released with OpenBSD 5.3. Maintained by YASUOKA Masahiko.

Library functions that originated in OpenBSD

arc4random(3): David Mazieres, December 28, 1996, OpenBSD 2.1
bcrypt(3): Implemented by Niels Provos and David Mazieres based on the blowfish(3) hash function by Bruce Schneier (1993). Imported February 13, 1997 and first released with OpenBSD 2.1.
strlcpy(3), strlcat(3): Todd Miller and Theo de Raadt, July 1, 1998, OpenBSD 2.4
strtonum(3): Ted Unangst, Todd Miller, and Theo de Raadt, May 3, 2004, OpenBSD 3.6
imsg: Message passing API, written by Henning Brauer. In libutil since May 26, 2010, OpenBSD 4.8; used by various daemons before that.
timingsafe_bcmp(3): Damien Miller, July 13, 2010, OpenBSD 4.9
explicit_bzero(3): Ted Unangst and Matthew Dempsky, January 22, 2014, OpenBSD 5.5
ohash: Written and maintained by Marc Espie. In libutil since May 12, 2014, OpenBSD 5.6; used by make(1) and m4(1) before that.
asr: Replacement resolver written and maintained by Eric Faurot. Imported April 14, 2012; activated on March 26, 2014, OpenBSD 5.6.
reallocarray(3): Theo de Raadt and Ted Unangst, April 22, 2014, OpenBSD 5.6
getentropy(2): Matthew Dempsky and Theo de Raadt, June 13, 2014, OpenBSD 5.6
sendsyslog(2): Theo de Raadt, July 10, 2014, OpenBSD 5.6
timingsafe_memcmp(3): Matthew Dempsky, July 13, 2014, OpenBSD 5.6
pledge(2): Theo de Raadt, July 19, 2015, OpenBSD 5.9

Projects maintained by OpenBSD developers outside OpenBSD

sudo: Started by Bob Coggeshall and Cliff Spencer around 1980. Imported November 18, 1999, first released with OpenBSD 2.7. Now maintained by Todd Miller.
midish: Written and maintained by Alexandre Ratchov. Port available since November 4, 2005.
fdm: Written and maintained by Nicholas Marriott. Port available since January 18, 2007.
toad: Written and maintained by Antoine Jacoutot. Port available since October 8, 2013.
portroach: Written and maintained by Jasper Lievisse Adriaanse, originally forked from FreeBSD's portscout. Port available since September 5, 2014.