OpenBSD Hackathons

In June of 1999, OpenBSD held the first hackathon. In the months leading up to this, either Theo or Niels Provos had coined this new word hackathon. A bunch of developers from around the world congregated into a house in Calgary, and within the week had the first IPv6 and IPSEC stacks completely integrated into an operating system... an industry first.. an accidental scrape in a hardwood floor commemorates the event.

In succeeding years, the OpenBSD development process has benefited greatly from holding more of these events. In our form, hackathons do not have talks, nor a specific schedule. People will arrive at a hackathon to work for a straight stretch of time on the projects they wish to, in the same room as the people who they need to talk to about their ideas. Hackathons are about writing code. At hackathons there is an attempt to get new changes into the source tree quickly. Since people from many different timezones are in the same room, development is almost around the clock. Developers sometimes joke about returning home without jet-lag.

Hackathon attendees come by invitation only. Some new people in the community who show promise are sometimes invited to see if they have what it takes. However, hackathons are not developer training events.

The event space and accommodation is typically funded by donations to the OpenBSD Project, or by the OpenBSD Foundation, however most developers pay for their own travel. The facilities are always chosen to be highly economical; generally near Universities or in cheaper locales. If anyone wants to help us FUND ONE OF THESE EVENTS OR A DEVELOPER'S TRAVEL, please contact Theo de Raadt (who generally has the most knowledge about upcoming options), or directly offer travel expenses to a developer for the next event. General financing is more interesting, but we will entertain offers for free locations as well.

Here are some details about past and future events, also showing a part of the artwork from the event T-shirt (if there was one made). The shirts are only given to people who attend the event, and are worn with pride. Every shirt contains at least one developer in-joke, so don't worry if you can't understand the shirt. Just enjoy them.

l2k25: leipzig hackathon
Jul 30 - Aug 05, 2025
Leipzig, Germany
28 developers
Funded by The OpenBSD Foundation and with the assistance of genua.

j2k25: japan hackathon
May 18 - 25, 2025
Nara, Japan
28 developers
Funded by The OpenBSD Foundation and with the assistance of Yasuoka Masahiko.

h2k24: hackathon
Nov 3 - 10, 2024
Valencia, Spain
24 developers
Funded by The OpenBSD Foundation

c2k24: hackathon
Jul 8 - 15, 2024
Prague, Tyrsuv dum, Czech Republic
26 developers
Funded by The OpenBSD Foundation

p2k24: ports hackathon
Apr 12 - 19, 2024
Ottery St. Mary, UK
17 developers and an itinerant cat
Funded by The OpenBSD Foundation and with the support of Stuart Henderson and Cadhay.

l2k24: Focused on LibreSSL
Mar 26 - Apr 1, 2024
Melbourne, Australia
12 developers
Funded by The OpenBSD Foundation

h2k23: hackathon
Nov 7 - 13, 2023
Coimbra, Portugal
18 developers
Funded by The OpenBSD Foundation and with the support of University of Coimbra and the portuguese usual suspects.

p2k23: ports hackathon
September 1 - 7, 2023
Dublin, Ireland
26 developers
Funded by The OpenBSD Foundation and NCSC Ireland and with the support of Tom Smyth.

g2k23: general hackathon
July 2 - 9, 2023
Tallinn, Estonia
20 developers
Funded by The OpenBSD Foundation.

w2k23: wifi nano hackathon
May 11 - 17, 2023
Toulouse, France
4 developers
Funded by The OpenBSD Foundation and with the support of Martin Pieuchot.

m2k23: mini hackathon
Apr 23- 29, 2023
Marrakech, Morocco
22 developers
Funded by The OpenBSD Foundation.

h2k22: hackathon
Nov 5 - 12, 2022
Lousa, Portugal
22 developers
Funded by OpenBSD Foundation and with the support of Pedro Almeida.

g2k22: hackathon
Aug 29 - Sep 4, 2022
Burg Liebenzell, Germany
25 developers
Funded by genua and the OpenBSD Foundation.

r2k22: hackathon
Jun 25 - Jul 1, 2022
Bruges, Belgium
24 developers
Funded by The OpenBSD Foundation and with the support of Stefan Sperling.

h2k21: hackathon
Oct 20 - Oct 28, 2021
Gouveia, Portugal
21 developers
Funded by The OpenBSD Foundation and with the support of Pedro Almeida and the Municipality of Gouveia.

k2k21: hackathon
Aug 29 - Sep 4, 2021
Burg Liebenzell, Germany
26 developers
Funded by genua.

k2k20: german mini hackathon
Sep 11 - 17, 2020
Burg Liebenzell, Germany
14 developers
Funded by genua.

a2k20: antipodian hackathon
Jan 20 - 27, 2020
Hobart, Tasmania, Australia
17 developers
Funded by The OpenBSD Foundation and with the support of Ross L Richardson.

u2k20: uckermark hackathon
Jan 12 - 17, 2020
Uckermark, Germany
14 developers
Supported by The OpenBSD Foundation and Seehotel Huberhof.

e2k19: elk lakes cabin hackathon
Nov 25 - 30, 2019
Elk Lakes Cabin, BC, Canada
13 developers
Funded by The OpenBSD Foundation and with the support of Xplornet.

p2k19: ports hackathon
Nov 5 - 12, 2019
Bucharest, Romania
18 developers
Funded by The OpenBSD Foundation, and supported by Faculty of Mathematics and Computer Science, University of Bucharest.

g2k19: general hackathon
May 7 - 14, 2019
Ottawa, Canada
43 developers
Funded by The OpenBSD Foundation.

t2k19: taipei mini hackathon
Mar 28 - Apr 5, 2019
Taipei, Taiwan
16 developers
Funded by The OpenBSD Foundation and with the support of Kevin Lo and MSI/FUNTORO

a2k19: antipodean mini hackathon
Jan 17-24, 2019
Wellington, New Zealand
18 developers
Supported by the Victoria University of Wellington and funded by The OpenBSD Foundation.

l2k18: libressl mini hackathon
Nov 3-11, 2018
Edmonton, Canada
5 developers
Supported by The OpenBSD Foundation.

n2k18: network hackathon
Sept 6-11, 2018
Ústí nad Labem, Czech Republic
11 developers
Supported by Univerzita Jana Evangelisty Purkyně and funded by Oracle and The OpenBSD Foundation.

g2k18: general hackathon
Jul 8-13, 2018
Ljubljana, Slovenia
39 developers
Funded by The OpenBSD Foundation and with the support of Mitja Muženič.

p2k18: ports (and pledge) hackathon
Apr 23-29, 2018
Nantes, France
24 developers
Funded by The OpenBSD Foundation and with the support of Epitech Nantes.

a2k18: antipodean hackathon
Feb 5-11, 2018
Dunedin, New Zealand
19 developers
Funded by The OpenBSD Foundation and with the support of University of Otago.

s2k17: snowshoe hackathon
Nov 26 - 29, 2017
Elk Lakes Cabin, BC, Canada
10 developers
Funded by ForeTell Technologies and with the support of Xplornet.

p2k17: ports hackathon
Nov 1 - 6, 2017
Berlin, Germany
23 developers
Funded by The OpenBSD Foundation with the support of IN-Berlin and Hostserver.

t2k17: general hackathon
Aug 9 - 15, 2017
Toronto, Canada
38 developers
Funded by The OpenBSD Foundation and with the support of University of Toronto.

d2k17: network mini-hackathon
May 26 - 31, 2017
Starnberg, Germany
24 developers
Funded by The OpenBSD Foundation and with the support of genua.

e2k17: nano-hackathon
March 25 - 28, 2017
Edmonton, Canada
5 developers
With the support of Bob Beck.

a2k17: antipodean hackathon
Jan 19 - 26, 2017
Brisbane, Australia
19 developers
Funded by The OpenBSD Foundation and with the support of David Gwynne.

l2k16: libressl hackathon
Nov 2 - 6, 2016
Toulouse, France
9 developers
Funded by The OpenBSD Foundation with the help of ENSEEIHT and Objectif Libre.

b2k16: budapest ports hackathon
Oct 31 - Nov 5, 2016
Budapest, Hungary
10 developers
Funded by The OpenBSD Foundation.

g2k16: general hackathon
Aug 30 - Sep 5, 2016
Cambridge, UK
62 developers
Funded by The OpenBSD Foundation with the help of Computer Laboratory, Cambridge.

n2k16: network hackathon
Jul 18 - 22, 2016
Prague, Czech Republic
18 developers
Funded by The OpenBSD Foundation and Oracle, with the help of Charles University.

p2k16: ports hackathon
Apr 25 - 29, 2016
Nantes, France
22 developers
Funded by The OpenBSD Foundation and with the support of Epitech Nantes.

n2k15: network MP hackathon
Dec 1 - 6, 2015
Hannover, Germany
19 developers
Funded by The OpenBSD Foundation and with the support of Esdenera Networks.

u2k15: utf8 hackathon
Oct 22 - 27, 2015
Berlin, Germany
22 developers
Funded by The OpenBSD Foundation and with the support of IN-Berlin.

l2k15: libressl hackathon
Sep 8 - 13, 2015
Faculty of Organization and Informatics, Varaždin, Croatia
17 developers
Funded by The OpenBSD Foundation with help of the Open Systems and Security Lab.

j2k15: uefi hackathon
Aug 30 - Sep 2, 2015
Nasu, Tochigi, Japan
6 developers
With the support of IIJ innovation institute.

c2k15: general hackathon
Jul 15 - 21, 2015
Calgary, Canada
45 developers
Funded by The OpenBSD Foundation and with the support of SAIT.

p2k15: ports mini hackathon
Apr 2 - 7, 2015
Exeter, UK
14 developers
Funded by The OpenBSD Foundation and with the support of Andy Henderson.

s2k15: southern mini hackathon
Feb 6 - 13, 2015
Brisbane, Australia
21 developers
Funded by The OpenBSD Foundation and with the support of David Gwynne.

g2k14: general hackathon
July 8 - 14, 2014
Ljubljana, Slovenia
49 developers
Funded by The OpenBSD Foundation and with the support of Mitja Muženič.

m2k14: mini hackathon
Apr 17 - 22, 2014
Marrakech, Morocco
12 developers
Funded by The OpenBSD Foundation and with the support of Université Cadi Ayyad.

n2k14: mini hackathon
Jan 18 - 25, 2014
Dunedin, New Zealand
15 developers
Funded by ForeTell Technologies and with the support of University of Otago.

b2k13: mini hackathon
Oct 17 - 21, 2013
Berlin, Germany
21 developers
Funded by The OpenBSD Foundation and with the support of IN-Berlin.

t2k13: general hackathon
May 29 - Jun 5, 2013
Toronto, Canada
43 developers
Funded by The OpenBSD Foundation and with the support of University of Toronto.

n2k13: network hackathon
Jan 13 - 19, 2013
Dunedin, New Zealand
17 developers
Funded by The OpenBSD Foundation and with the support of University of Otago.

c2k12: coimbra hackathon
Nov 14 - 20, 2012
Coimbra, Portugal
10 developers
Funded by The OpenBSD Foundation and with the support of University of Coimbra.

p2k12: ports hackathon
Oct 8 - 13, 2012
Budapest, Hungary
9 developers
Funded by donations to The OpenBSD Project.

n2k12: network hackathon
Sep 17 - 21, 2012
Starnberg, Germany
23 developers
Funded by genua.

g2k12: general hackathon
Jul 7 - 14, 2012
Budapest, Hungary
41 developers
Funded by The OpenBSD Foundation.

r2k12: rthreads hackathon
Apr 10 - 14, 2012
Paris, France
16 developers
Funded by The OpenBSD Foundation and support of Institute Henri Poincaré and Paris-Sud University.

p2k11: Ports hackathon
Nov 12 - 18, 2011
Budapest, Hungary
15 developers
Funded by donations to the OpenBSD Project.

a2k11: ARM hackathon
Nov 5 - 12, 2011
Coimbra, Portugal
8 developers
Funded by The OpenBSD Foundation and with the support of University of Coimbra.

s2k11: General hackathon
Sep 16 - 23, 2011
Ljubljana, Slovenia
25 developers
Funded by The OpenBSD Foundation and with the support of Mitja Muženič.

c2k11: General hackathon
Jul 2 - 9, 2011
Edmonton, Alberta, Canada
36 developers
Funded by The OpenBSD Foundation.

k2k11: Kernel hackathon
Apr 1 - 7, 2011
Hafnarfjordur, Iceland
15 developers
Funded by The OpenBSD Foundation.

p2k10: Ports hackathon
Oct 23 - 29, 2010
Budapest, Hungary
19 developers
Funded by donations to the OpenBSD Project.

j2k10: mini-hackathon in Japan
Sep 19 - 25, 2010
Akiyamago, Sakae Mura, Nagano, Japan
19 developers

c2k10: General hackathon
Jun 25 - Jul 3, 2010
Edmonton, Alberta, Canada
46 developers
Funded by The OpenBSD Foundation.

n2k10: Network hackathon
Jan 9 - 15, 2010
Melbourne, Australia
17 developers
Funded by The OpenBSD Foundation and support of Victorian Partnership for Advanced Computing

h2k9: Hardware hackathon
Nov 21 - 27, 2009
Coimbra, Portugal
15 developers
Funded by donations to the OpenBSD Project and with the support of University of Coimbra.

p2k9: Ports hackathon
Oct 9 - 16, 2009
Budapest, Hungary
14 developers
Funded by donations to the OpenBSD Project.

f2k9: Filesystem/uvm hackathon
Aug 7 - 14, 2009
Stockholm, Sweden
14 developers
Funded by .se Foundation.

c2k9: General hackathon
May 30 - Jun 7, 2009
Edmonton, Alberta, Canada
46 developers
Funded by donations to the OpenBSD Project.

n2k9: Network hackathon
Jan 26 - 30, 2009
Basel, Switzerland
19 developers

h2k8: Hardware hackathon
Nov 20 - 27, 2008
Coimbra, Portugal
18 developers
Funded by donations to the OpenBSD Project and with the support of University of Coimbra.

p2k8: Ports hackathon
Oct 24 - 31, 2008
Budapest, Hungary
13 developers
Funded by donations to the OpenBSD Project.

c2k8: General hackathon
June 6-15, 2008
Edmonton, Alberta, Canada
55 developers
Funded by The OpenBSD Foundation.

n2k8: Network hackathon
May 5-10, 2008
Ito, Japan
18 developers
Funded by donations to the OpenBSD Project and Mark Uemura.

h2k7: Hardware hackathon
Nov 22 - 29, 2007
Coimbra, Portugal
11 developers
Funded by donations to the OpenBSD Project and with the support of University of Coimbra.

p2k7: Focused on ports
Oct 22 - 28, 2007
Budapest, Hungary
13 developers
Funded by donations to the OpenBSD Project.

c2k7: General hackathon
May 25 - Jun 2, 2007
Calgary, Alberta, Canada
50 developers
Funded by donations to the OpenBSD Project.

f2k7: Focused on Filesystems
Apr 10 - 15, 2007
Vienna, Austria
14 developers
Funded by donations to the OpenBSD Project.

h2k6: Focused on drivers for hardware
Nov 25 - 30, 2006
Coimbra, Portugal
14 developers
Funded by donations to the OpenBSD Project and with the support of University of Coimbra.

p2k6: Focused on ports
Oct 18 - 22, 2006
Budapest, Hungary
14 developers
Funded by donations to the OpenBSD Project.

k2k6: Focused on IPSEC and IKE
Aug 28 - Sep 1, 2006
Schloss Kransberg, Germany
14 developers

r2k6: Focused on network routing
Jun 14 - 18, 2006
Hamburg, Germany
6 developers
Support of Henning Brauer.

c2k6: General hackathon
May 21 - 29, 2006
Calgary, Alberta, Canada
47 developers
Funded by donations to the OpenBSD Project.

v2k5: Focused on ports
Nov 1 - 4, 2005
San Servolo, Venice, Italy
12 developers
Funded by donations to the OpenBSD Project.

c2k5: General hackathon
May 21 - 28, 2005
Calgary, Alberta, Canada
60 developers
Funded by donations to the OpenBSD Project.

c2k4: General hackathon
Jun 19 - 26, 2004
Calgary, Alberta, Canada
46 developers
Funded by donations to the OpenBSD Project.

pf2k4: Focused on pf development
Apr 24 - 28, 2004
Sechelt, BC, Canada
12 developers
Support of Ryan McBride.

c2k3: General hackathon
May 8 - 20, 2003
Calgary, Alberta, Canada
51 developers
Funded by NLnet (after DARPA pulled out their support).

c2k2: General hackathon
Jun 4 - 12, 2002
Calgary, Alberta, Canada
42 developers
Funded by DARPA.

c2k1-2: Focused on sparc64
Aug 17 - 20, 2001
Washington, DC
Funded by DARPA with support of USENIX.

c2k1: Birth of PF
Jun 21 - 26, 2001
Cambridge, Massachusetts
25 developers
Funded by DARPA with the support of MIT.

c2k: General hackathon
Jun 15 - 18, 2000
Calgary, Alberta, Canada
18 developers
Funded by donations to the OpenBSD Project.

c99: Focused on IPSEC
Jun 4 - 6, 1999
Calgary, Alberta, Canada
10 developers
Funded by Theo de Raadt.