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 HylaFAX (originally known as FlexFAX, but renamed due to copyright issues), 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, Leffler also worked at Lucasfilm, Pixar Animation Studios, Silicon Graphics, Alias Research, Softimage 3D, Cinetron Computer Systems and VMware. It while he was at Silicon Graphics that he developed HylaFAX. Later, Leffler became an independent system design consultant.[1]