Poul-Henning Kamp (; born 1966) is a Danish computer software developer known for work on various projects including

FreeBSD FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular ...

and

Varnish Varnish is a clear transparent hard protective coating or film. It is not a stain. It usually has a yellowish shade from the manufacturing process and materials used, but it may also be pigmented as desired, and is sold commercially in various ...

. He currently resides in

Slagelse Slagelse () is a town on Zealand, Denmark. The town is the seat of Slagelse Municipality, and is the biggest town of the municipality. It is located 15 km east of Korsør, 16 km north-east of Skælskør, 33 km south-east of Kalundborg and 14 km ...

, Denmark.

Involvement in the FreeBSD project

Poul-Henning Kamp has been committing to the

project for most of its duration. He is responsible for the widely used MD5crypt implementation of the MD5 password hash algorithm, a vast quantity of systems code including the FreeBSD GEOM storage layer,

GBDE GBDE, standing for GEOM Based Disk Encryption, is a block device-layer disk encryption system written for FreeBSD, initially introduced in version 5.0. It is based on the GEOM disk framework. GBDE was designed and implemented by Poul-Henning Kamp an ...

cryptographic storage transform, part of the UFS2 file system implementation,

FreeBSD Jail The jail mechanism is an implementation of FreeBSD's OS-level virtualisation that allows system administrators to partition a FreeBSD-derived computer system into several independent mini-systems called ''jails'', all sharing the same kernel, with ...

malloc C dynamic memory allocation refers to performing manual memory management for dynamic memory allocation in the C programming language via a group of functions in the C standard library, namely , , , and . The C++ programming language includes ...

library, and the FreeBSD and NTP timecounters code.

Varnish cache

He is the lead architect and developer for the open source Varnish cache project, an

HTTP accelerator A web accelerator is a proxy server that reduces website access time. They can be a self-contained hardware appliance or installable software. Web accelerators may be installed on the client computer or mobile device, on ISP servers, on the server ...

Dispute with D-Link

In 2006, Kamp had a dispute with electronics manufacturer

D-Link D-Link Corporation is a Taiwanese multinational networking equipment manufacturing corporation headquartered in Taipei, Taiwan. It was founded in March 1986 in Taipei as ''Datex Systems Inc.'' History D-Link Corporation changed its name fr ...

in which he claimed they were committing NTP vandalism by embedding the IP address of his NTP servers in their routers. The dispute was resolved in April 2006.

Other

A post by Kamp on the FreeBSD mailing lists is responsible for the popularization of the term ''bike shed discussion'', and the derived term ''bikeshedding'', to describe

Parkinson's law of triviality The law of triviality is C. Northcote Parkinson's 1957 argument that people within an organization commonly or typically give disproportionate weight to trivial issues. Parkinson provides the example of a fictional committee whose job was to ap ...

open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...

projects - when the amount of discussion that a subject receives is inversely proportional to its importance. Poul-Henning Kamp is known for his preference of a

Beerware Beerware is a tongue-in-cheek term for software released under a very relaxed license (beerware licensed software). It provides the end user with the right to use a particular program (or do anything else with the source code). Description Sh ...

license A license (or licence) is an official permission or permit to do, use, or own something (as well as the document of that permission or permit). A license is granted by a party (licensor) to another party (licensee) as an element of an agreeme ...

to the

GNU General Public License The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the Four Freedoms (Free software), four freedoms to run, study, share, and modify the software. The license was th ...

(GPL).

Anti-semitism accusations

On May 8, 2019, Kamp tweeted "I thought anti-semitism was *unfounded* hatred of Jews? If you hate them because they did something awful, like implement apartheid, it is not anti-semitism, but perfectly justified critique of people who in particular should know better than that." In a blog post later, he wrote that "I will readily admit that it was probably not my most skilled use of Twitter, but I stand by my point", explaining the point in more nuance. In the blog post, Kamp goes on to say that "Jews everywhere in the world should be appalled and up in arms over the atrocities against UN's Human Rights being done in the name of their religion", and that he "detest the vast silent majority of them who fail to do so."

Publications

Poul-Henning Kamp has published a substantial number of articles over the years in publications like

Communications of the ACM ''Communications of the ACM'' is the monthly journal of the Association for Computing Machinery (ACM). It was established in 1958, with Saul Rosen as its first managing editor. It is sent to all ACM members. Articles are intended for readers with ...

and

ACM Queue ''ACM Queue'' is a bimonthly computer magazine founded and published by the Association for Computing Machinery The Association for Computing Machinery (ACM) is a US-based international learned society for computing. It was founded in 1947 an ...

mostly on the topics of computing and time keeping. A selection of publications:
USENIX ATC 1998 FREENIX track, "malloc(3) Revisited"

* ttps://web.archive.org/web/20050916085901/http://www.acmqueue.org/modules.php?name=Content&pa=showpage&pid=170 ACM Queue: Building Systems to be Shared Securely
ACM Queue: You're doing it wrong

ACM Queue: A Generation Lost in the Bazaar

Communications of the ACM 2011: The Most Expensive One-Byte Mistake

Communications of the ACM 2011: The One-Second War

References

External links

people.freebsd.org homepage

phk.freebsd.dk homepage

Blog in Danish

Another blog in Danish

Resolution of D-Link Dispute

Varnish cache
{{DEFAULTSORT:Kamp, Poul-Henning 1966 births Living people Danish computer programmers Danish computer scientists Free software programmers FreeBSD people Articles containing video clips People from Slagelse