Example image of eyePlorer eyePlorer map for 'Computer Systems Research Group': AT&T DARPA Operating system University of California, Berkeley Unix Bob Fabry University of California Berkeley Software Distribution ARPANET Application programming interface Berkeley sockets Unix File System USL v. BSDi FreeBSD Kernel Normal Form NetBSD OpenBSD Free Software Foundation Linux Open source Bill Joy Keith Bostic Marshall Kirk McKusick Berkeley Software Design BIND BSD/OS Nvi Mach (kernel) Computer Consoles Inc. BSD Daemon Yggdrasil Linux/GNU/X Bourne shell List of operating systems