He is responsible for the widely used MD5crypt implementation of the MD5 password hash algorithm,[2][3] a vast quantity of systems code including the FreeBSD GEOM storage layer, GBDE cryptographic storage transform, part of the UFS2 file system implementation, FreeBSD Jails, the phkmalloc implementation of the malloc library call, and the FreeBSD and NTP timecounters code,[4] and the nanokernel interface with David Mills.
[5] He is the lead architect and developer for the open source Varnish cache project, an HTTP accelerator.
[8] A post by Kamp on the FreeBSD mailing lists[9][10] is responsible for the popularization of the term bike shed discussion, and the derived term bikeshedding, to describe Parkinson's law of triviality in open source projects - when the amount of discussion that a subject receives is inversely proportional to its importance.
[11] Poul-Henning Kamp has published a substantial number of articles over the years in publications like Communications of the ACM and ACM Queue mostly on the topics of computing and time keeping.
A selection of publications: Media related to Poul-Henning Kamp at Wikimedia Commons