Samuel J. Leffler

Samuel J Leffler is a computer scientist, known for
his extensive work on BSD, from the 1980s to FreeBSD in the
present day. Among other projects, he created FlexFAX,
libtiff, and the FreeBSD Wireless
Device Drivers.
The "Design and Implementation" series of books, which he co-authored, 
While working for the Computer Systems Research Group (CSRG, UC Berkeley) at University of California, Berkeley, Leffler helped with 4.1 and 4.2 BSD release. He has contributed to almost every aspect of BSD systems, including the networking subsystem. After leaving Computer Systems Research Group, Mr. Leffler also worked at Lucasfilm, Pixar Animation Studios, Silicon Graphics, Alias Research, Softimage 3D, Cinetron Computer Systems and VMware. Later he became an independent consultant on system design.