Xv6


xv6 is a modern reimplementation of Sixth Edition Unix in ANSI C for multiprocessor x86 and RISC-V systems. It is used for pedagogical purposes in MIT's Operating Systems Engineering course as well as Georgia Tech's Design of Operating Systems Course, IIIT Hyderabad, IIIT Delhi and as well as many other institutions.

Purpose

Unlike Linux or BSD, xv6 is simple enough to cover in a semester, yet still contains the important concepts and organization of Unix. Rather than study the original V6 code, the course uses xv6 since PDP-11 machines are not widely available and the original operating system was written in archaic pre-ANSI C.

Self-documentation

One feature of the Makefile for xv6 is the option to produce a PDF of the entire source code listing in a readable format. The entire printout is only 99 pages, including cross references. This is reminiscent of the original V6 source code, which was published in a similar form in Lions' Commentary on UNIX 6th Edition, with Source Code.

Educational use

xv6 has been used in operating systems courses at many universities including
Northwestern University,
The George Washington University, Northeastern University, Yale University, Columbia University, Ben-Gurion University, Johns Hopkins University, Portland State University, Tsinghua University,
Southern Adventist University, the University of Wisconsin–Madison, Binghamton University, the University of Utah,
University of California, Irvine, University of California, Riverside, IIIT Bangalore, IIIT Allahabad, IIT Bombay, IIT Delhi, IIT Madras, IIT Bhubaneswar and PEC Chandigarh in India,
the Linnaeus University in Sweden,
the University of Otago in New Zealand,
the National University of Córdoba, the National University of Río Cuarto, in Argentina,
the Federico Santa María Technical University in Chile, the Università degli Studi di Palermo University of Illinois at Chicago, Rutgers University, the Università degli Studi di Modena e Reggio Emilia in Italy, the University of Tehran in Iran, Slovak University of Technology in Bratislava in Slovakia, Federal University of Minas Gerais in Brazil and the
Technion – Israel Institute of Technology, in Israel.