xv6 is a re-implementation of Unix Version 6 (v6), which was developed
by Dennis Ritchie and Ken Thompson. xv6 follows the structure and
style of v6, but is implemented for a modern x86-based multiprocessor
using ANSI C.

xv6 is inspired by the following work by Lions about Unix version 6:

- Lions' Commentary on UNIX' 6th Edition, John Lions, Peer to Peer
Communications; ISBN: 1-57398-013-7; 1st edition (June 14, 2000). See
also http://pdos.csail.mit.edu/6.828/2006/v6.html, which provides
pointers to on-line resources for v6.