xref: /freebsd/share/misc/bsd-family-tree (revision 208b7e81bf5b5fc1b044f3f096b5bcecb16146c1)

The UNIX system family tree: Research and BSD
---------------------------------------------

First Edition (V1)
     |
Second Edition (V2)
     |
Third Edition (V3)
     |
Fourth Edition (V4)
     |
Fifth Edition (V5)
     |
Sixth Edition (V6) -----*
       \                |
        \               |
         \              |
Seventh Edition (V7)    |
            \           |
             \        1BSD
             32V        |
               \      2BSD---------------*
                \    /                   |
                 \  /                    |
                  \/                     |
                 3BSD                    |
                  |                      |
               4.0BSD                2.79BSD
                  |                      |
               4.1BSD --------------> 2.8BSD
                  |                      |
              4.1aBSD -----------\       |
                  |                \     |
              4.1bBSD                \   |
                  |                    \ |
      *------ 4.1cBSD --------------> 2.9BSD
     /            |                      |
Eighth Edition    |                   2.9BSD-Seismo
     |            |                      |
     +----<--- 4.2BSD               2.9.1BSD
     |            |                      |
     +----<--- 4.3BSD -------------> 2.10BSD
     |            |               /      |
Ninth Edition     |              / 2.10.1BSD
     |         4.3BSD Tahoe-----+        |
     |            |              \       |
     |            |                \     |
     v            |                  2.11BSD
Tenth Edition     |                      |
                  |                  2.11BSD rev #430
               4.3BSD NET/1              |
                  |                      v
               4.3BSD Reno
                  |
   *---------- 4.3BSD NET/2 -------------------+-------------*
   |                    |                      |             |
386BSD 0.0              |                      |           BSD/386 ALPHA
   |                    |                      |             |
386BSD 0.1 ------------>+                      |           BSD/386 0.3.[13]
   |     \              |                  4.4BSD Alpha      |
   |     386BSD 1.0     |                      |           BSD/386 0.9.[34]
   |                    |                  4.4BSD            |
   |                    |                    / |             |
   |                    |   4.4BSD-Encumbered  |             |
   |                -NetBSD 0.8                |           BSD/386 1.0
   |               /    |                      |             |
FreeBSD 1.0 <-----'  NetBSD 0.9                |           BSD/386 1.1
   |                    |           .----- 4.4BSD Lite       |
FreeBSD 1.1             |          /   /       |     \       |
   |                    |         /   /        |      \      |
FreeBSD 1.1.5       .---|--------'   /         |       \     |
   |               /    |           /          |        \    |
FreeBSD 1.1.5.1   /     |          /           |         \   |
   |             /   NetBSD 1.0 <-'            |          \  |
   |            /       |                      |           \ |
FreeBSD 2.0 <--'        |                      |           BSD/OS 2.0
   |                     \                     |             |
FreeBSD 2.0.5             \                    |           BSD/OS 2.0.1
   |                 .-----\------------- 4.4BSD Lite2       |
   |                 |      \             |  |   |   |       |
   |                 | .-----|------Rhapsody |   |   |       |
   |                 | |     |        NetBSD 1.3 |   |       |
   |                 | |     |           OpenBSD 2.3 |       |
   |                 | |     |                BSD/OS 3.0     |
FreeBSD 2.1          | |     |                               |
 |   |               | |  NetBSD 1.1 ------.               BSD/OS 2.1
 | FreeBSD 2.1.5     | |     |              \                |
 |     |             | |  NetBSD 1.2         \             BSD/OS 3.0
 | FreeBSD 2.1.6     | |     |  \          OpenBSD 2.0       |
 |     |             | |     |   \             |             |
 | FreeBSD 2.1.6.1   | |     |    \            |             |
 |     |             | |     |     \           |             |
 | FreeBSD 2.1.7     | |     |      |          |             |
 |     |             | |     |  NetBSD 1.2.1   |             |
 | FreeBSD 2.1.7.1   | |     |                 |             |
 |                   | |     |                 |             |
 |                   | |     |                 |             |
 *-FreeBSD 2.2       | |     |                 |             |
 |        \          | |     |                 |             |
 |     FreeBSD 2.2.1 | |     |                 |             |
 |         |         | |     |                 |             |
 |     FreeBSD 2.2.2 | |     |             OpenBSD 2.1       |
 |         |         | |     |                 |             |
 |     FreeBSD 2.2.5 | |     |                 |             |
 |         |         | |     |             OpenBSD 2.2       |
 |         |         | |  NetBSD 1.3           |             |
 |     FreeBSD 2.2.6 | |     |    |            |             |
 |         |         | |     | NetBSD 1.3.1    |           BSD/OS 3.1
 |         |         | |     |    |        OpenBSD 2.3       |
 |         |         | |     | NetBSD 1.3.2    |             |
 |     FreeBSD 2.2.7 | |     |    |            |             |
 |         |         | |     |    |            |           BSD/OS 4.0
 |     FreeBSD 2.2.8 | |     |    |            |             |
 |         |         | |     |    |            |             |
 |         v         | |     |    |        OpenBSD 2.4       |
 |     FreeBSD 2.2.9 | |     |    |            |             |
 |                   | |     |    |            |             |
FreeBSD 3.0 <--------* |     |    v            |             |
 |                     |     | NetBSD 1.3.3    |             |
 *---FreeBSD 3.1       |     |                 |             |
 |       |             |     |                 |           BSD/OS 4.0.1
 |   FreeBSD 3.2----*  |  NetBSD 1.4       OpenBSD 2.5       |
 |       |          |  |  |  |    |            |             |
 |       |          |  |  |  |    |            |             |
 |       |          |  |  |  |    |            |             |
 |   FreeBSD 3.3    |  |  |  | NetBSD 1.4.1    |             |
 |       |          |  |  |  |    |        OpenBSD 2.6       |
 |   FreeBSD 3.4    |  |  |  |    |            |             |
 |           |      |  |  |  |    |            |           BSD/OS 4.1
FreeBSD 4.0  |      |  |  |  | NetBSD 1.4.2    |             |
 |           |      |  |  |  |    |            |             |
 |           |      |  |  |  |    |            |             |
 |   FreeBSD 3.5    |  |  |  |    |        OpenBSD 2.7       |
 |           |      |  |  |  |    |            |             |
 |   FreeBSD 3.5.1  |  |  |  |    |            |             |
 |                  |  |  |  |    |            |             |
 *---FreeBSD 4.1    |  |  |  |    |            |             |
 |      |           |  | (?) |    |            |             |
 |   FreeBSD 4.1.1  |  |  /  |    |            |             |
 |      |           |  | /   |    |            |             |
 |   FreeBSD 4.2   Darwin/   | NetBSD 1.4.3    |             |
 |      |         Mac OS X   |             OpenBSD 2.8     BSD/OS 4.2
 |      |             |      |                 |             |
 |      |             |      |                 |             |
 |      |           10.0  NetBSD 1.5           |             |
 |   FreeBSD 4.3      |      |    |            |             |
 |      |             |      |    |        OpenBSD 2.9       |
 |      |             |      | NetBSD 1.5.1    |             |
 |      |             |      |    |            |             |
 |   FreeBSD 4.4-.    |      | NetBSD 1.5.2    |             |
 |      |        | Mac OS X  |    |            |             |
 |      |        |   10.1    |    |        OpenBSD 3.0       |
 |   FreeBSD 4.5 |    |      |    |            |             |
 |      |         \   |      |    |            |           BSD/OS 4.3
 |   FreeBSD 4.6   \  |      |    |        OpenBSD 3.1       |
 |      |           \ |      | NetBSD 1.5.3    |             |
 |   FreeBSD 4.6.2 Mac OS X  |                 |             |
 |      |            10.2    |                 |             |
 |   FreeBSD 4.7      |      |                 |             |
 |      |             |   NetBSD 1.6       OpenBSD 3.2       |
 |   FreeBSD 4.8      |      |    |            |             |
 |      |             |      | NetBSD 1.6.1    |             |
 |      |--------.    |      |    |        OpenBSD 3.3     BSD/OS 5.0
 |      |         \   |      |    |            |             |
 |   FreeBSD 4.9   |  |      |    |        OpenBSD 3.4     BSD/OS 5.1 ISE
 |      |          |  |      |    |            |
 |      |          |  |      | NetBSD 1.6.2    |
 |      |          |  |      |    |            |
 |      |          |  |      |    |        OpenBSD 3.5
 |      |          |  |      |    v            |
 |   FreeBSD 4.10  |  |      |                 |
 |      |          |  |      |                 |
 |   FreeBSD 4.11  |  |      |                 |
 |                 |  |      |                 |
 |                  `-|------|-----------------|---------------------.
 |                    |      |                 |                      \
FreeBSD 5.0           |      |                 |                       |
 |                    |      |                 |                       |
FreeBSD 5.1           |      |                 |                DragonFly 1.0
 |          \         |      |                 |                       |
 |           ----- Mac OS X  |                 |                       |
 |                   10.3    |                 |                       |
FreeBSD 5.2           |      |                 |                       |
 |      |             |      |                 |                       |
 |   FreeBSD 5.2.1    |      |                 |                       |
 |                    |      |                 |                       |
 *-------FreeBSD 5.3  |      |                 |                       |
 |           |        |      |             OpenBSD 3.6                 |
 |           |        |   NetBSD 2.0           |                       |
 |           |        |      | |  |            |               DragonFly 1.2.0
 |           |     Mac OS X  | | NetBSD 2.0.2  |                       |
 |           |       10.4    | |  |            |                       |
 |       FreeBSD 5.4  |      | |  |            |                       |
 |           |        |      | |  |        OpenBSD 3.7                 |
 |           |        |      | | NetBSD 2.0.3  |                       |
 |           |        |      | |  |            |                       |
 *--FreeBSD  |        |      | |  v        OpenBSD 3.8                 |
 |    6.0    |        |      | |               |                       |
 |     |     |        |      |  \              |                       |
 |     |     |        |      | NetBSD 2.1      |                       |
 |     |     |        |      |                 |                       |
 |     |     |        |   NetBSD 3.0           |                       |
 |     |     |        |      | |  |            |               DragonFly 1.4.0
 |     |     |        |      | |  |        OpenBSD 3.9                 |
 |  FreeBSD  |        |      | |  |            |                       |
 |    6.1    |        |      | |  |            |                       |
 |     |  FreeBSD 5.5 |      | |  |            |                       |
 |     |              |      | | NetBSD 3.0.1  |               DragonFly 1.6.0
 |     |              |      | |  |            |                       |
 |     |              |      | |  |        OpenBSD 4.0                 |
 |     |              |      | | NetBSD 3.0.2  |                       |
 |     |              |      | NetBSD 3.1      |                       |
 | FreeBSD 6.2        |      |                 |                       |
 |     |              |      |                 |               DragonFly 1.8.0
 |     |              |      |             OpenBSD 4.1                 |
 |     |              |      |                 |               DragonFly 1.10.0
 |     |           Mac OS X  |                 |                       |
 |     |             10.5    |                 |                       |
 |     |              |      |             OpenBSD 4.2                 |
 |     |              |   NetBSD 4.0           |                       |
 | FreeBSD 6.3        |      |    |            |                       |
 |            \       |      |    |            |                       |
 *--FreeBSD    |      |      |    |            |               DragonFly 1.12.0
 |    7.0      |      |      |    |            |                       |
 |     |       |      |      |    |        OpenBSD 4.3                 |
 |     |       |      |      | NetBSD          |               DragonFly 2.0.0
 |     |    FreeBSD   |      |  4.0.1      OpenBSD 4.4                 |
 |     |      6.4     |      |                 |                       |
 |     |              |      |                 |                       |
 |  FreeBSD 7.1       |      |                 |                       |
 |     |              |      |                 |               DragonFly 2.2.0
 |  FreeBSD 7.2       |   NetBSD 5.0       OpenBSD 4.5                 |
 |             \      |      | |    \          |                       |
 |              |  Mac OS X  | |     \         |                       |
 |              |    10.6    | |      \        |                       |
 |              |     |      | |   NetBSD      |               DragonFly 2.4.0
 |              |     |      | |    5.0.1  OpenBSD 4.6                 |
 |              |     |      | |       |       |                       |
 *--FreeBSD     |     |      | |       |       |                       |
 |    8.0       |     |      | |       |       |                       |
 |     |     FreeBSD  |      | |   NetBSD      |                       |
 |     |       7.3    |      | |    5.0.2      |               DragonFly 2.6.0
 |     |        |     |      | |           OpenBSD 4.7                 |
 |  FreeBSD     |     |      | |               |                       |
 |    8.1       |     |      | |               |                       |
 |     |        |     |      | |               |               DragonFly 2.8.2
 |     |        |     |      | |           OpenBSD 4.8                 |
 |     |        |     |      | *--NetBSD       |                       |
 |  FreeBSD  FreeBSD  |      | |    5.1        |                       |
 |    8.2      7.4    |      | |      |        |               DragonFly 2.10.1
 |     |              |      | |      |    OpenBSD 4.9                 |
 |     `-----.     Mac OS X  | |      |        |                       |
 |            \      10.7    | |      |        |                       |
 |             |      |      | |      |    OpenBSD 5.0                 |
 *--FreeBSD    |      |      | |      |        |                       |
 |    9.0      |      |      | |   NetBSD      |               DragonFly 3.0.1
 |     |    FreeBSD   |      | |    5.1.2      |                       |
 |     |      8.3     |      | |      |        |                       |
 |     |       |      |      | |   NetBSD      |                       |
 |     |       |      |      | |    5.1.3      |                       |
 |     |       |      |      | |      |        |                       |
 |     |       |      |      | |   NetBSD      |                       |
 |     |       |      |      | |    5.1.4      |                       |
 |     |       |      |      | |           OpenBSD 5.1                 |
 |     |       |   Mac OS X  | `----.          |                       |
 |     |       |     10.8    |       \         |                       |
 |     |       |      |   NetBSD 6.0  |        |                       |
 |     |       |      |      | | |    |    OpenBSD 5.2         DragonFly 3.2.1
 |  FreeBSD    |      |      | | | NetBSD      |                       |
 |    9.1      |      |      | | |   5.2       |                       |
 |     |       |      |      | | |    |        |                       |
 |     |       |      |      | | | NetBSD      |                       |
 |     |       |      |      | | |  5.2.1      |                       |
 |     |       |      |      | | |    |        |                       |
 |     |       |      |      | | | NetBSD      |                       |
 |     |       |      |      | | |  5.2.2      |                       |
 |     |       |      |      | | |             |                       |
 |     |       |      |      | |  \            |                       |
 |     |       |      |      | |   NetBSD      |                       |
 |     |       |      |      | |    6.0.1      |                       |
 |     |       |      |      | |      |   OpenBSD 5.3          DragonFly 3.4.1
 |     |       |      |      | |   NetBSD      |                       |
 |     |       |      |      | |    6.0.2      |                       |
 |     |       |      |      | |      |        |                       |
 |     |       |      |      | |   NetBSD      |                       |
 |     |       |      |      | |    6.0.3      |                       |
 |     |       |      |      | |      |        |                       |
 |     |       |      |      | |   NetBSD      |                       |
 |     |       |      |      | |    6.0.4      |                       |
 |     |       |      |      | |      |        |                       |
 |     |       |      |      | |   NetBSD      |                       |
 |     |       |      |      | |    6.0.5      |                       |
 |     |       |      |      | |               |                       |
 |     |       |      |      | |`-NetBSD 6.1   |                       |
 |     |    FreeBSD   |      |       |         |                       |
 |     |      8.4     |      |    NetBSD 6.1.1 |                       |
 |     |              |      |       |         |                       |
 |  FreeBSD           |      |    NetBSD 6.1.2 |                       |
 |    9.2          Mac OS X  |       |         |                       |
 |     |             10.9    |       |    OpenBSD 5.4                  |
 |     `-----.        |      |       |         |               DragonFly 3.6.0
 |            \       |      |       |         |                       |
 *--FreeBSD    |      |      |    NetBSD 6.1.3 |                       |
 |   10.0      |      |      |       |         |                       |
 |     |       |      |      |       |         |               DragonFly 3.6.1
 |     |       |      |      |       |         |                       |
 |     |       |      |      |       |         |                       |
 |     |       |      |      |       |         |               DragonFly 3.6.2
 |     |       |      |      |    NetBSD 6.1.4 |                       |
 |     |       |      |      |       |         |                       |
 |     |       |      |      |       |    OpenBSD 5.5                  |
 |     |       |      |      |       |         |                       |
 |     |       |      |      |       |         |               DragonFly 3.8.0
 |     |       |      |      |       |         |                       |
 |     |       |      |      |       |         |                       |
 |     |       |      |      |       |         |               DragonFly 3.8.1
 |     |       |      |      |       |         |                       |
 |     |       |      |      |       |         |                       |
 |     |       |      |      |       |         |               DragonFly 3.6.3
 |     |       |      |      |       |         |                       |
 |     |    FreeBSD   |      |       |         |                       |
 |     |      9.3     |      |       |         |                       |
 |     |              |      |    NetBSD 6.1.5 |               DragonFly 3.8.2
 |     |           Mac OS X  |                 |                       |
 |     |             10.10   |                 |                       |
 |     |              |      |            OpenBSD 5.6                  |
 |  FreeBSD           |      |                 |                       |
 |   10.1             |      |                 |               DragonFly 4.0.1
 |     |              |      |                 |                       |
 |     |              |      |                 |               DragonFly 4.0.2
 |     |              |      |                 |                       |
 |     |              |      |                 |               DragonFly 4.0.3
 |     |              |      |                 |                       |
 |     |              |      |                 |               DragonFly 4.0.4
 |     |              |      |                 |                       |
 |     |              |      |                 |               DragonFly 4.0.5
 |     |              |      |                 |                       |
 |     |              |      |            OpenBSD 5.7                  |
 |     |              |      |                 |               DragonFly 4.2.0
 |  FreeBSD           |      |                 |                       |
 |   10.2             |      |                 |                       |
 |     |            OS X  NetBSD 7.0           |                       |
 |     |            10.11    |            OpenBSD 5.8                  |
 |     |              |      |                 |               DragonFly 4.4.1
 |  FreeBSD           |      |            OpenBSD 5.9                  |
 |   10.3             |      |                 |                       |
 |                    |   NetBSD 7.0.1         |                       |
 |                    |      |                 |               DragonFly 4.6.0
 |                    |      |                 |                       |
 |                    |      |                 |                       |
 *--FreeBSD         macOS    |            OpenBSD 6.0                  |
 |   11.0           10.12    |                 |                       |
 |     |              |   NetBSD 7.1           |                       |
 |     |              |      |                 |               DragonFly 4.8.0
 |     |              |      |            OpenBSD 6.1                  |
 |  FreeBSD           |      |                 |                       |
 |   11.1             |      |                 |                       |
 |                    |      |                 |                       |
FreeBSD 12 -current   |  NetBSD -current  OpenBSD -current    DragonFly -current
 |                    |      |                 |                       |
 v                    v      v                 v                       v

Time
----------------

Time tolerance +/- 6 months, depending on which book/article you read; if it
was the announcement in Usenet or if it was available as tape.

[44B] McKusick, Marshall Kirk, Keith Bostic, Michael J Karels,
	and John Quarterman. The Design and Implementation of
	the 4.4BSD Operating System.
[APL] Apple website [http://www.apple.com/macosx/]
[BSDI] Berkeley Software Design, Inc.
[DFB] DragonFlyBSD Project, The.
[DOC] README, COPYRIGHT on tape.
[FBD] FreeBSD Project, The.
[KB]  Keith Bostic. BSD2.10 available from Usenix. comp.unix.sources,
	Volume 11, Info 4, April, 1987.
[KKK] Mike Karels, Kirk McKusick, and Keith Bostic. tahoe announcement.
	comp.bugs.4bsd.ucb-fixes, June 15, 1988.
[KSJ] Michael J. Karels, Carl F. Smith, and William F. Jolitz.
	Changes in the Kernel in 2.9BSD. Second Berkeley Software
	Distribution UNIX Version 2.9, July, 1983.
[NBD] NetBSD Project, The.
[OBD] OpenBSD Project, The.
[QCU] Salus, Peter H. A quarter century of UNIX.
[SMS] Steven M. Schultz. 2.11BSD, UNIX for the PDP-11.
[TUHS] The Unix Historical Society.  http://minnie.tuhs.org/Unix_History/.
[USE] Usenet announcement.
[WRS] Wind River Systems, Inc.
[dmr] Dennis Ritchie, via E-Mail

Multics                 1965
UNIX                    Summer 1969
				DEC PDP-7
First   Edition         1971-11-03 [QCU]
				DEC PDP-11/20, Assembler
Second  Edition         1972-06-12 [QCU]
				10 UNIX installations
Third   Edition         1973-02-xx [QCU]
				Pipes, 16 installations
Fourth  Edition         1973-11-xx [QCU]
				rewriting in C effected,
                                above 30 installations
Fifth   Edition         1974-06-xx [QCU]
				above 50 installations
Sixth   Edition         1975-05-xx [QCU]
				port to DEC Vax
Seventh Edition         1979-01-xx [QCU]
				first portable UNIX
Eighth  Edition         1985-02-xx [QCU]
				VAX 11/750, VAX 11/780 [dmr]
				descended from 4.1c BSD [dmr]
				descended from 4.1 BSD [44B]
			scooping-out and replacement of the character-device
			and networking part by the streams mechanism

Ninth   Edition         1986-09-xx [QCU]
Tenth   Edition         1989-10-xx [QCU]

1BSD                    late 1977
			1978-03-09 [QCU]
				PDP-11, Pascal, ex(1)
				30 free copies of 1BSD sent out
				35 tapes sold for 50 USD [QCU]
2BSD                    mid 1978 [QCU] 1979-05-10 [TUHS]
				75 2BSD tapes shipped
2.79BSD			1980-04-xx [TUHS]
2.8BSD			1981-07-xx [KSJ]

2.8.1BSD		1982-01-xx [QCU]
				set of performance improvements
2.9BSD			1983-07-xx [KSJ]
2.9.1BSD                1983-11-xx [TUHS]
2.9BSD-Seismo		1985-08-xx [SMS]
2.10BSD			1987-04-xx [KKK]
2.10.1BSD		1989-01-xx [SMS]
2.11BSD			1992-02-xx [SMS]
2.11BSD rev #430	1999-12-13 [SMS]

32V			1978-1[01]-xx [QCU]
3BSD                    late 1979 [QCU] March 1980 [TUHS]
				virtual memory, page replacement,
                        	demand paging
4.0BSD                  1980-10-xx
4.1BSD                  1981-07-08 [DOC]
4.1aBSD                 1982-04-xx
				alpha release, 100 sites, networking [44B]
4.1bBSD				internal release, fast filesystem [44B]
4.1cBSD                 late 1982
				beta release, IPC [44B]
4.2BSD                  1983-09-xx [QCU]
                        1983-08-03 [DOC]
4.3BSD                  1986-06-xx [QCU]
			1986-04-05 [KB], [DOC]
4.3BSD Tahoe            1988-06-15 [QCU], [DOC]
4.3BSD NET/1            1988-11-xx [QCU]
                        1989-01-01 [DOC]
4.3BSD Reno             1990-06-29 [QCU], [DOC]
4.3BSD NET/2            1991-06-28 [QCU], [DOC]

BSD/386 ALPHA		1991-12-xx [BSDI]
				first code released to people outside BSDI
386BSD 0.0              1992-02-xx [DOC]
BSD/386 0.3.1	        1992-04-xx [BSDI] first ext. beta; B customers
BSD/386 0.3.3		1992-06-xx [BSDI] first CDROM version
386BSD 0.1              1992-07-28 [DOC]
4.4BSD Alpha            1992-07-07
BSD/386 0.9.3		1992-10-xx [BSDI]
				first external gamma; G customers
BSD/386 0.9.4		1992-12-xx [BSDI]
				would have been 1.0 except for request
				for preliminary injunction
BSD/386 1.0 		1993-03-xx [BSDI]
				injunction denied; first official release
NetBSD 0.8              1993-04-20 [NBD]
4.4BSD                  1993-06-01 [USE]
NetBSD 0.9              1993-08-23 [NBD]
FreeBSD 1.0		1993-11-01 [FBD]
FreeBSD 1.0.2		1993-11-14 [FBD]
				supersedes 1.0 13 days after release.
BSD/386 1.1		1994-02-xx [BSDI]
4.4BSD Lite             1994-03-01 [USE]
FreeBSD 1.1		1994-05-07 [FBD]
FreeBSD 1.1.5		1994-06-30 [FBD]
FreeBSD 1.1.5.1		1994-07-05 [FBD]
				supersedes 1.1.5 5 days after release.
NetBSD 1.0              1994-10-26 [NBD]
386BSD 1.0              1994-11-12 [USE]
FreeBSD 2.0		1994-11-23 [FBD]
BSD/OS 2.0		1995-01-xx [BSDI] 4.4 lite based
FreeBSD 2.0.5		1995-06-10 [FBD]
BSD/OS 2.0.1		1995-06-xx [BSDI]
4.4BSD Lite Release 2	1995-06-xx [44B]
				the true final distribution from the CSRG
FreeBSD 2.1.0		1995-11-19 [FBD]
NetBSD 1.1              1995-11-26 [NBD]
BSD/OS 2.1		1996-01-xx [BSDI]
FreeBSD 2.1.5		1996-07-14 [FBD]
NetBSD 1.2              1996-10-04 [NBD]
OpenBSD 2.0             1996-10-18 [OBD]
FreeBSD 2.1.6		1996-11-16 [FBD]
FreeBSD 2.1.6.1		1996-11-25 [FBD] (sendmail security release)
Rhapsody		1997-xx-xx
FreeBSD 2.1.7		1997-02-20 [FBD]
BSD/OS 3.0		1997-02-xx [BSDI] 4.4 lite2 based
FreeBSD 2.2.0		1997-03-16 [FBD]
FreeBSD 2.2.1		1997-03-25 [FBD]
FreeBSD 2.2.2		1997-05-16 [FBD]
NetBSD 1.2.1            1997-05-20 [NBD] (patch release)
OpenBSD 2.1             1997-06-01 [OBD]
FreeBSD 2.2.5		1997-10-22 [FBD]
OpenBSD 2.2             1997-12-01 [OBD]
NetBSD 1.3              1998-01-04 [NBD]
FreeBSD 2.2.6		1998-03-25 [FBD]
NetBSD 1.3.1            1998-03-09 [NBD] (patch release)
BSD/OS 3.1		1998-03-xx [BSDI]
OpenBSD 2.3             1998-05-19 [OBD]
NetBSD 1.3.2            1998-05-29 [NBD] (patch release)
FreeBSD 2.2.7		1998-07-22 [FBD]
BSD/OS 4.0		1998-08-xx [BSDI]
				2-lock MP support, ELF executables
FreeBSD 3.0		1998-10-16 [FBD]
				FreeBSD-3.0 is a snapshot from -current,
				while 3.1 and 3.2 are from 3.x-stable which
				was branched quite some time after 3.0-release
FreeBSD 2.2.8           1998-11-29 [FBD]
OpenBSD 2.4             1998-12-01 [OBD]
NetBSD 1.3.3            1998-12-23 [NBD] (patch release)
FreeBSD 3.1		1999-02-15 [FBD]
BSD/OS 4.0.1		1999-03-xx [BSDI]
NetBSD 1.4              1999-05-12 [NBD]
FreeBSD 3.2             1999-05-17 [FBD]
OpenBSD 2.5             1999-05-19 [OBD]
NetBSD 1.4.1            1999-08-26 [NBD] (patch release)
FreeBSD 3.3             1999-09-17 [FBD]
OpenBSD 2.6             1999-12-01 [OBD]
FreeBSD 3.4             1999-12-20 [FBD]
BSD/OS 4.1		1999-12-xx [BSDI]
FreeBSD 4.0             2000-03-13 [FBD]
NetBSD 1.4.2            2000-03-19 [NBD] (patch release)
OpenBSD 2.7             2000-06-15 [OBD]
FreeBSD 3.5		2000-06-24 [FBD]
FreeBSD 4.1		2000-07-27 [FBD]
FreeBSD 3.5.1		2000-07-28 [FBD]
FreeBSD 4.1.1		2000-09-25 [FBD] (a network-only patch release)
FreeBSD 4.2  		2000-11-21 [FBD]
NetBSD 1.4.3		2000-11-25 [NBD] (patch release)
BSD/OS 4.2		2000-11-29 [BSDI]
OpenBSD 2.8		2000-12-01 [OBD]
NetBSD 1.5              2000-12-06 [NBD]
Mac OS X 10.0           2001-03-24 [APL]
FreeBSD 4.3  		2001-04-20 [FBD]
OpenBSD 2.9  		2001-06-01 [OBD]
NetBSD 1.5.1		2001-07-11 [NBD] (patch release)
NetBSD 1.5.2		2001-09-13 [NBD] (patch release)
FreeBSD 4.4  		2001-09-18 [FBD]
Mac OS X 10.1		2001-09-29 [APL]
OpenBSD 3.0		2001-12-01 [OBD]
FreeBSD 4.5  		2002-01-29 [FBD]
BSD/OS 4.3		2002-03-14 [WRS]
OpenBSD 3.1		2002-05-19 [OBD]
FreeBSD 4.6  		2002-06-15 [FBD]
NetBSD 1.5.3		2002-07-22 [NBD] (patch release)
FreeBSD 4.6.2		2002-08-15 [FBD] (patch release)
Mac OS X 10.2		2002-08-23 [APL]
NetBSD 1.6		2002-09-14 [NBD]
FreeBSD 4.7		2002-10-08 [FBD]
OpenBSD 3.2		2002-11-01 [OBD]
FreeBSD 5.0		2003-01-17 [FBD]
				FreeBSD 5.0 is a separate branch off of
				-current, similar to 3.0.
FreeBSD 4.8		2003-04-03 [FBD]
NetBSD 1.6.1		2003-04-21 [NBD] (patch release)
OpenBSD 3.3		2003-05-01 [OBD]
BSD/OS 5.0		2003-05-?? [WRS]
FreeBSD 5.1		2003-06-09 [FBD]
Mac OS X 10.3		2003-10-24 [APL]
FreeBSD 4.9		2003-10-28 [FBD]
BSD/OS 5.1 ISE		2003-10-?? [WRS] (final version)
OpenBSD 3.4		2003-11-01 [OBD]
FreeBSD 5.2		2004-01-12 [FBD]
FreeBSD 5.2.1		2004-02-22 [FBD] (patch release)
NetBSD 1.6.2		2004-03-01 [NBD] (patch release)
OpenBSD 3.5		2004-04-01 [OBD]
FreeBSD 4.10		2004-05-27 [FBD]
DragonFly 1.0		2004-07-12 [DFB]
OpenBSD 3.6		2004-10-29 [OBD]
FreeBSD 5.3		2004-11-06 [FBD]
NetBSD 2.0		2004-12-09 [NBD]
FreeBSD 4.11		2005-01-25 [FBD]
DragonFly 1.2.0		2005-04-08 [DFB]
NetBSD 2.0.2		2005-04-14 [NBD] (security/critical release)
Mac OS X 10.4		2005-04-29 [APL]
FreeBSD 5.4		2005-05-09 [FBD]
OpenBSD 3.7		2005-05-19 [OBD]
NetBSD 2.0.3		2005-10-31 [NBD] (security/critical release)
OpenBSD 3.8		2005-11-01 [OBD]
FreeBSD 6.0		2005-11-01 [FBD]
NetBSD 2.1		2005-11-02 [NBD]
NetBSD 3.0		2005-12-23 [NBD]
DragonFly 1.4.0		2006-01-08 [DFB]
FreeBSD 2.2.9		2006-04-01 [FBD]
OpenBSD 3.9		2006-05-01 [OBD]
FreeBSD 6.1		2006-05-08 [FBD]
FreeBSD 5.5		2006-05-25 [FBD]
NetBSD 3.0.1		2006-07-24 [NBD] (security/critical release)
DragonFly 1.6.0		2006-07-24 [DFB]
OpenBSD 4.0		2006-11-01 [OBD]
NetBSD 3.0.2		2006-11-04 [NBD] (security/critical release)
NetBSD 3.1		2006-11-04 [NBD]
FreeBSD 6.2		2007-01-15 [FBD]
DragonFly 1.8.0		2007-01-30 [DFB]
OpenBSD 4.1		2007-05-01 [OBD]
DragonFly 1.10.0	2007-08-06 [DFB]
Mac OS X 10.5		2007-10-26 [APL]
OpenBSD 4.2		2007-11-01 [OBD]
NetBSD 4.0		2007-12-19 [NBD]
FreeBSD 6.3		2008-01-18 [FBD]
DragonFly 1.12.0	2008-02-26 [DFB]
FreeBSD 7.0		2008-02-27 [FBD]
OpenBSD 4.3		2008-05-01 [OBD]
DragonFly 2.0.0		2008-07-21 [DFB]
OpenBSD 4.4		2008-11-01 [OBD]
FreeBSD 6.4		2008-11-28 [FBD]
FreeBSD 7.1		2009-01-04 [FBD]
DragonFly 2.2.0		2009-02-17 [DFB]
NetBSD 5.0		2009-04-29 [NBD]
OpenBSD 4.5		2009-05-01 [OBD]
FreeBSD 7.2		2009-05-04 [FBD]
Mac OS X 10.6		2009-06-08 [APL]
NetBSD 5.0.1		2009-08-02 [NBD] (security/critical release)
DragonFly 2.4.0		2009-09-16 [DFB]
OpenBSD 4.6		2009-10-18 [OBD]
FreeBSD 8.0		2009-11-26 [FBD]
NetBSD 5.0.2		2010-02-12 [NBD] (security/critical release)
FreeBSD 7.3		2010-03-23 [FBD]
DragonFly 2.6.0		2010-03-28 [DFB]
OpenBSD 4.7		2010-05-19 [OBD]
FreeBSD 8.1		2010-07-24 [FBD]
DragonFly 2.8.2		2010-10-30 [DFB]
OpenBSD 4.8		2010-11-01 [OBD]
NetBSD 5.1		2010-11-19 [NBD]
FreeBSD 7.4		2011-02-24 [FBD]
FreeBSD 8.2		2011-02-24 [FBD]
DragonFly 2.10.1	2011-04-26 [DFB]
OpenBSD 4.9		2011-05-01 [OBD]
Mac OS X 10.7		2011-07-20 [APL]
OpenBSD 5.0		2011-11-01 [OBD]
FreeBSD 9.0		2012-01-12 [FBD]
NetBSD 5.1.2		2012-02-02 [NBD] (security/critical release)
DragonFly 3.0.1		2012-02-21 [DFB]
FreeBSD 8.3		2012-04-18 [FBD]
OpenBSD 5.1		2012-05-01 [OBD]
Mac OS X 10.8		2012-07-25 [APL]
NetBSD 6.0		2012-10-17 [NBD]
OpenBSD 5.2		2012-11-01 [OBD]
DragonFly 3.2.1		2012-11-02 [DFB]
NetBSD 5.2		2012-12-03 [NBD]
NetBSD 6.0.1		2012-12-26 [NBD] (security/critical release)
FreeBSD 9.1		2012-12-30 [FBD]
DragonFly 3.4.1		2013-04-29 [DFB]
OpenBSD 5.3		2013-05-01 [OBD]
NetBSD 6.0.2		2013-05-18 [NBD] (security/critical release)
NetBSD 6.1		2013-05-18 [NBD]
FreeBSD 8.4		2013-06-07 [FBD]
NetBSD 6.1.1		2013-08-22 [NBD]
NetBSD 5.1.3		2013-09-29 [NBD]
NetBSD 5.2.1		2013-09-29 [NBD]
FreeBSD 9.2		2013-09-30 [FBD]
NetBSD 6.0.3		2013-09-30 [NBD]
NetBSD 6.1.2		2013-09-30 [NBD]
Mac OS X 10.9		2013-10-22 [APL]
OpenBSD 5.4		2013-11-01 [OBD]
DragonFly 3.6.0 	2013-11-25 [DFB]
FreeBSD 10.0		2014-01-20 [FBD]
NetBSD 5.1.4		2014-01-25 [NBD]
NetBSD 5.2.2		2014-01-25 [NBD]
NetBSD 6.0.4		2014-01-25 [NBD]
NetBSD 6.1.3		2014-01-25 [NBD]
DragonFly 3.6.1 	2014-02-22 [DFB]
DragonFly 3.6.2		2014-04-10 [DFB]
NetBSD 6.0.5		2014-04-12 [NDB]
NetBSD 6.1.4		2014-04-12 [NDB]
OpenBSD 5.5		2014-05-01 [OBD]
DragonFly 3.8.0		2014-06-04 [DFB]
DragonFly 3.8.1		2014-06-16 [DFB]
DragonFly 3.6.3		2014-06-17 [DFB]
FreeBSD 9.3		2014-07-05 [FBD]
DragonFly 3.8.2		2014-08-08 [DFB]
NetBSD 6.1.5		2014-09-22 [NBD]
Mac OS X 10.10		2014-10-16 [APL]
OpenBSD 5.6		2014-11-01 [OBD]
FreeBSD 10.1		2014-11-14 [FBD]
DragonFly 4.0.1		2014-11-25 [DFB]
DragonFly 4.0.2		2015-01-07 [DFB]
DragonFly 4.0.3		2015-01-21 [DFB]
DragonFly 4.0.4		2015-03-09 [DFB]
DragonFly 4.0.5		2015-03-23 [DFB]
OpenBSD 5.7		2015-05-01 [OBD]
DragonFly 4.2.0		2015-06-29 [DFB]
FreeBSD 10.2            2015-08-13 [FBD]
NetBSD 7.0		2015-09-25 [NBD]
OS X 10.11		2015-09-30 [APL]
OpenBSD 5.8		2015-10-18 [OBD]
DragonFly 4.4.1		2015-12-07 [DFB]
OpenBSD 5.9		2016-03-29 [OBD]
FreeBSD 10.3		2016-04-04 [FBD]
NetBSD 7.0.1		2016-05-22 [NBD]
DragonFly 4.6.0		2016-08-02 [DFB]
OpenBSD 6.0		2016-09-01 [OBD]
macOS 10.12		2016-09-20 [APL]
FreeBSD 11.0		2016-10-10 [FBD]
NetBSD 7.1		2017-03-11 [NBD]
DragonFly 4.8.0		2017-03-27 [DFB]
OpenBSD 6.1		2017-04-11 [OBD]
FreeBSD 11.1		2017-07-26 [FBD]

Bibliography
------------------------

Leffler, Samuel J., Marshall Kirk McKusick, Michael J Karels and John
Quarterman. The Design and Implementation of the 4.3BSD UNIX Operating
System. Reading, Mass. Addison-Wesley, 1989. ISBN 0-201-06196-1

Salus, Peter H. A quarter century of UNIX. Addison-Wesley Publishing
Company, Inc., 1994. ISBN 0-201-54777-5

McKusick, Marshall Kirk, Keith Bostic, Michael J Karels, and John
Quarterman. The Design and Implementation of the 4.4BSD Operating
System. Reading, Mass. Addison-Wesley, 1996. ISBN 0-201-54979-4

McKusick, Marshall Kirk, George Neville-Neil. The Design and
Implementation of the FreeBSD Operating System.
Addison-Wesley Professional, Published: Aug 2, 2004. ISBN 0-201-70245-2

McKusick, Marshall Kirk, George Neville-Neil, Robert Watson. The
Design and Implementation of the FreeBSD Operating System, 2nd Edition.
Pearson Education, Inc., 2014. ISBN 0-321-96897-2

Doug McIlroy. Research Unix Reader.

Michael G. Brown. The Role of BSD in the Development of Unix.
Presented to the Tasmanian Unix Special Interest Group of the
Australian Computer Society, Hobart, August 1993.

Peter H. Salus. Unix at 25. Byte Magazine, October 1994.
URL: http://www.byte.com/art/9410/sec8/art3.htm

Andreas Klemm, Lars Köller. If you're going to San Francisco ...
Die freien BSD-Varianten von Unix. c't April 1997, page 368ff.

BSD Release Announcements collection.
URL: http://www.FreeBSD.org/releases/

BSD Hypertext Man Pages
URL: http://www.FreeBSD.org/cgi/man.cgi

UNIX history graphing project
URL: http://minnie.tuhs.org/Unix_History/index.html

UNIX history
URL: http://www.levenez.com/unix/

James Howard: The BSD Family Tree
URL: http://ezine.daemonnews.org/200104/bsd_family.html
("what are the differences between FreeBSD, NetBSD, and OpenBSD?")


Acknowledgments
---------------

Josh Gilliam for suggestions, bug fixes, and finding very old
original BSD announcements from Usenet or tapes.

Steven M. Schultz for providing 2.8BSD, 2.10BSD, 2.11BSD manual pages.

--
Copyright (c) 1997-2012 Wolfram Schneider <wosch@FreeBSD.ORG>
URL: http://svnweb.freebsd.org/base/head/share/misc/bsd-family-tree

$FreeBSD$