Michael (Mike) J. Karels

Key contributor to the history of BSD UNIX, Karels was an American software engineer who graduated from the University of Notre Dame with a Bachelor of Science in Microbiology. He went on to the University of California, Berkeley for his advanced degree in Microbiology. He had access to the department's computer, and since the administrator of that PDP-11 did not have enough time, he started helping him and then making changes to the system.

Karels began his contribution to Unix with the 2.9BSD release, distributed for the PDP-11. When he saw a job posting with the Computer Systems Research Group in the BSD project, he decided to jump in. In 1982 he took over Bill Joy's responsibilities when Bill left CSRG, and served as the system architect for 4.3BSD, the most important BSD release and the base of development for a number of commercial Unix flavors available today, including Solaris. This release was introduced to the world in deep detail through the all-time famous book, "The Design and Implementation of the 4.3BSD UNIX Operating System." He was a CSRG principal programmer for eight years.

He worked closely with Van Jacobson on a number of widely accepted algorithms in TCP implementation, including the Jacobson/Karels algorithm TCP slow start and the routing radix tree — probably the most famous ones. Being a very down-to-earth person, Karels spent little time taking credit for this work and, on the other hand, used every opportunity to mention the names of people who had in one way or another some role or contribution to the TCP/IP implementation in Unix.

In 1993, the USENIX Association gave a Lifetime Achievement Award (Flame) to the Computer Systems Research Group at the University of California, Berkeley, honoring 180 individuals, among whom he was included, having contributed to the CSRG's 4.4BSD-Lite release. Later, he moved to BSDi (Berkeley Software Design) and designed BSD/OS, which was for years the only commercially available BSD-style Unix on the Intel platform. BSD/OS is a very reliable OS platform designed for Internet services. BSDi's software assets were bought by Wind River in April 2001, and Karels joined Wind River as Principal Technologist for the BSD/OS platform. From 2009, he served as Sr. Principal Engineer at McAfee.

Among the publications to which he contributed are: with S. Leffler, M. McKusick, and J. Quarterman: "The Design and Implementation of the 4.3BSD UNIX Operating System," Addison-Wesley, January 1989, ISBN 0-201-06196-1 — German translation published June 1990, ISBN 3-89319-239-5; Japanese translation published June 1991, ISBN 4-621-03607-6 (out of print); with S. Leffler and M. McKusick: "The Design and Implementation of the 4.3BSD UNIX Operating System Answer Book," Addison-Wesley, April 1991, ISBN 0-201-54629-9 — Japanese translation published January 1992, ISBN 4-8081-8039-5; and with M. McKusick, K. Bostic, and J. Quarterman: "The Design and Implementation of the 4.4BSD Operating System," Addison-Wesley, April 1996, ISBN 0-201-54979-4 — French translation published 1997, International Thomson Publishing, Paris, France, ISBN 2-84180-142-X.