1 The UNIX system family tree: Research and BSD
2 ---------------------------------------------
14 Sixth Edition (V6) -----*
18 Seventh Edition (V7) |
22 \ 2BSD---------------*
30 4.1BSD --------------> 2.8BSD
32 4.1aBSD -----------\ |
36 *------ 4.1cBSD --------------> 2.9BSD
38 Eighth Edition | 2.9BSD-Seismo
40 +----<--- 4.2BSD 2.9.1BSD
42 +----<--- 4.3BSD -------------> 2.10BSD
44 Ninth Edition | / 2.10.1BSD
45 | 4.3BSD Tahoe-----+ |
55 *---------- 4.3BSD NET/2 -------------------+-------------*
57 386BSD 0.0 | | BSD/386 ALPHA
59 386BSD 0.1 ------------>+ | BSD/386 0.3.[13]
61 | 386BSD 1.0 | | BSD/386 0.9.[34]
64 | | 4.4BSD-Encumbered | |
65 | NetBSD 0.8 | BSD/386 1.0
67 FreeBSD 1.0 NetBSD 0.9 | BSD/386 1.1
68 | | .----- 4.4BSD Lite |
69 FreeBSD 1.1 | / / | \ |
71 FreeBSD 1.1.5 .---|--------' / | \ |
73 FreeBSD 1.1.5.1 / | / | \ |
74 | / NetBSD 1.0 <-' | \ |
76 FreeBSD 2.0 <--' | | BSD/OS 2.0
78 FreeBSD 2.0.5 \ | BSD/OS 2.0.1
79 | .-----\------------- 4.4BSD Lite2 |
81 | | .-----|------Rhapsody | | | |
82 | | | | NetBSD 1.3 | | |
83 | | | | OpenBSD 2.3 | |
86 | | | | NetBSD 1.1 ------. BSD/OS 2.1
87 | FreeBSD 2.1.5 | | | \ |
88 | | | | NetBSD 1.2 \ BSD/OS 3.0
89 | FreeBSD 2.1.6 | | | \ OpenBSD 2.0 |
91 | FreeBSD 2.1.6.1 | | | \ | |
93 | FreeBSD 2.1.7 | | | | | |
94 | | | | | NetBSD 1.2.1 | |
95 | FreeBSD 2.1.7.1 | | | | |
98 *-FreeBSD 2.2 | | | | |
100 | FreeBSD 2.2.1 | | | | |
102 | FreeBSD 2.2.2 | | | OpenBSD 2.1 |
104 | FreeBSD 2.2.5 | | | | |
105 | | | | | OpenBSD 2.2 |
106 | | | | NetBSD 1.3 | |
107 | FreeBSD 2.2.6 | | | | | |
108 | | | | | NetBSD 1.3.1 | BSD/OS 3.1
109 | | | | | | OpenBSD 2.3 |
110 | | | | | NetBSD 1.3.2 | |
111 | FreeBSD 2.2.7 | | | | | |
112 | | | | | | | BSD/OS 4.0
114 | FreeBSD 2.2.8 | | | | | |
115 | | | | | OpenBSD 2.4 |
116 FreeBSD 3.0 <--------* | | v | |
117 | | | NetBSD 1.3.3 | |
118 *---FreeBSD 3.1 | | | |
119 | | | | | BSD/OS 4.0.1
120 | FreeBSD 3.2----* | NetBSD 1.4 OpenBSD 2.5 |
124 | FreeBSD 3.3 | | | | NetBSD 1.4.1 | |
125 | | | | | | | OpenBSD 2.6 |
126 | FreeBSD 3.4 | | | | | | |
127 | | | | | | | | BSD/OS 4.1
128 FreeBSD 4.0 | | | | | NetBSD 1.4.2 | |
131 | FreeBSD 3.5 | | | | | OpenBSD 2.7 |
133 | FreeBSD 3.5.1 | | | | | | |
135 *---FreeBSD 4.1 | | | | | | |
137 | FreeBSD 4.1.1 | | / | | | |
139 | FreeBSD 4.2 Darwin/ | NetBSD 1.4.3 | |
140 | | Mac OS X | OpenBSD 2.8 BSD/OS 4.2
143 | | 10.0 NetBSD 1.5 | |
144 | FreeBSD 4.3 | | | | |
145 | | | | | OpenBSD 2.9 |
146 | | | | NetBSD 1.5.1 | |
148 | FreeBSD 4.4-. | | NetBSD 1.5.2 | |
149 | | | Mac OS X | | | |
150 | | | 10.1 | | OpenBSD 3.0 |
151 | FreeBSD 4.5 | | | | | |
152 | | \ | | | | BSD/OS 4.3
153 | FreeBSD 4.6 \ | | | OpenBSD 3.1 |
154 | | \ | | NetBSD 1.5.3 | |
155 | FreeBSD 4.6.2 Mac OS X | | |
157 | FreeBSD 4.7 | | | |
158 | | | NetBSD 1.6 OpenBSD 3.2 |
159 | FreeBSD 4.8 | | | | |
160 | | | | NetBSD 1.6.1 | |
161 | |--------. | | | OpenBSD 3.3 BSD/OS 5.0
163 | FreeBSD 4.9 | | | | OpenBSD 3.4 BSD/OS 5.1 ISE
165 | | | | | NetBSD 1.6.2 |
167 | | | | | | OpenBSD 3.5
169 | FreeBSD 4.10 | | | |
171 | FreeBSD 4.11 | | | |
173 | `-|------|-----------------|---------------------.
177 FreeBSD 5.1 | | | DragonFly 1.0
179 | ----- Mac OS X | | |
183 | FreeBSD 5.2.1 | | | |
185 *-------FreeBSD 5.3 | | | |
186 | | | | OpenBSD 3.6 |
188 | | | | | | | DragonFly 1.2.0
189 | | Mac OS X | | NetBSD 2.0.2 | |
191 | FreeBSD 5.4 | | | | | |
192 | | | | | | OpenBSD 3.7 |
193 | | | | | NetBSD 2.0.3 | |
195 *--FreeBSD | | | | v OpenBSD 3.8 |
198 | | | | | NetBSD 2.1 | |
200 | | | | NetBSD 3.0 | |
201 | | | | | | | | DragonFly 1.4.0
202 | | | | | | | OpenBSD 3.9 |
203 | FreeBSD | | | | | | |
205 | | FreeBSD 5.5 | | | | | |
206 | | | | | NetBSD 3.0.1 | DragonFly 1.6.0
208 | | | | | | OpenBSD 4.0 |
209 | | | | | NetBSD 3.0.2 | |
210 | | | | NetBSD 3.1 | |
211 | FreeBSD 6.2 | | | |
212 | | | | | DragonFly 1.8.0
213 | | | | OpenBSD 4.1 |
214 | | | | | DragonFly 1.10.0
217 | | | | OpenBSD 4.2 |
219 | FreeBSD 6.3 | | | |
221 *--FreeBSD | | | | DragonFly 1.12.0
223 | | | | | OpenBSD 4.3 |
224 | | | | | | DragonFly 2.0.0
225 | | FreeBSD | | OpenBSD 4.4 |
228 | FreeBSD 7.1 | | | |
229 | | | | | DragonFly 2.2.0
230 | FreeBSD 7.2 | NetBSD 5.0 OpenBSD 4.5 |
234 | | | | | | DragonFly 2.4.0
235 | | | | | OpenBSD 4.6 |
237 *--FreeBSD | | | | | |
239 | | FreeBSD | | | | |
240 | | 7.3 | | | | DragonFly 2.6.0
241 | | | | | | OpenBSD 4.7 |
242 | FreeBSD | | | | | |
244 | | | | | | | DragonFly 2.8.2
245 | | | | | | OpenBSD 4.8 |
246 | | | | | NetBSD 5.1 | |
247 | FreeBSD FreeBSD | | | |
248 | 8.2 7.4 | | | DragonFly 2.10.1
249 | v | | OpenBSD 4.9 |
251 FreeBSD 9 -current | NetBSD -current OpenBSD -current |
258 Time tolerance +/- 6 months, depending on which book/article you read; if it
259 was the announcement in Usenet or if it was available as tape.
261 [44B] McKusick, Marshall Kirk, Keith Bostic, Michael J Karels,
262 and John Quarterman. The Design and Implementation of
263 the 4.4BSD Operating System.
264 [APL] Apple website [http://www.apple.com/macosx/]
265 [BSDI] Berkeley Software Design, Inc.
266 [DFB] DragonFlyBSD Project, The.
267 [DOC] README, COPYRIGHT on tape.
268 [FBD] FreeBSD Project, The.
269 [KB] Keith Bostic. BSD2.10 available from Usenix. comp.unix.sources,
270 Volume 11, Info 4, April, 1987.
271 [KKK] Mike Karels, Kirk McKusick, and Keith Bostic. tahoe announcement.
272 comp.bugs.4bsd.ucb-fixes, June 15, 1988.
273 [KSJ] Michael J. Karels, Carl F. Smith, and William F. Jolitz.
274 Changes in the Kernel in 2.9BSD. Second Berkeley Software
275 Distribution UNIX Version 2.9, July, 1983.
276 [NBD] NetBSD Project, The.
277 [OBD] OpenBSD Project, The.
278 [QCU] Salus, Peter H. A quarter century of UNIX.
279 [SMS] Steven M. Schultz. 2.11BSD, UNIX for the PDP-11.
280 [TUHS] The Unix Historical Society. http://minnie.tuhs.org/Unix_History/.
281 [USE] Usenet announcement.
282 [WRS] Wind River Systems, Inc.
283 [dmr] Dennis Ritchie, via E-Mail
288 First Edition 1971-11-03 [QCU]
289 DEC PDP-11/20, Assembler
290 Second Edition 1972-06-12 [QCU]
291 10 UNIX installations
292 Third Edition 1973-02-xx [QCU]
293 Pipes, 16 installations
294 Fourth Edition 1973-11-xx [QCU]
295 rewriting in C effected,
296 above 30 installations
297 Fifth Edition 1974-06-xx [QCU]
298 above 50 installations
299 Sixth Edition 1975-05-xx [QCU]
301 Seventh Edition 1979-01-xx [QCU]
303 Eighth Edition 1985-02-xx [QCU]
304 VAX 11/750, VAX 11/780 [dmr]
305 descended from 4.1c BSD [dmr]
306 descended from 4.1 BSD [44B]
307 scooping-out and replacement of the character-device
308 and networking part by the streams mechanism
310 Ninth Edition 1986-09-xx [QCU]
311 Tenth Edition 1989-10-xx [QCU]
315 PDP-11, Pascal, ex(1)
316 30 free copies of 1BSD sent out
317 35 tapes sold for 50 USD [QCU]
318 2BSD mid 1978 [QCU] 1979-05-10 [TUHS]
319 75 2BSD tapes shipped
320 2.79BSD 1980-04-xx [TUHS]
321 2.8BSD 1981-07-xx [KSJ]
323 2.8.1BSD 1982-01-xx [QCU]
324 set of performance improvements
325 2.9BSD 1983-07-xx [KSJ]
326 2.9.1BSD 1983-11-xx [TUHS]
327 2.9BSD-Seismo 1985-08-xx [SMS]
328 2.10BSD 1987-04-xx [KKK]
329 2.10.1BSD 1989-01-xx [SMS]
330 2.11BSD 1992-02-xx [SMS]
331 2.11BSD rev #430 1999-12-13 [SMS]
333 32V 1978-1[01]-xx [QCU]
334 3BSD late 1979 [QCU] March 1980 [TUHS]
335 virtual memory, page replacement,
338 4.1BSD 1981-07-08 [DOC]
340 alpha release, 100 sites, networking [44B]
341 4.1bBSD internal release, fast filesystem [44B]
343 beta release, IPC [44B]
344 4.2BSD 1983-09-xx [QCU]
346 4.3BSD 1986-06-xx [QCU]
347 1986-04-05 [KB], [DOC]
348 4.3BSD Tahoe 1988-06-15 [QCU], [DOC]
349 4.3BSD NET/1 1988-11-xx [QCU]
351 4.3BSD Reno 1990-06-29 [QCU], [DOC]
352 4.3BSD NET/2 1991-06-28 [QCU], [DOC]
354 BSD/386 ALPHA 1991-12-xx [BSDI]
355 first code released to people outside BSDI
356 386BSD 0.0 1992-02-xx [DOC]
357 BSD/386 0.3.1 1992-04-xx [BSDI] first ext. beta; B customers
358 BSD/386 0.3.3 1992-06-xx [BSDI] first CDROM version
359 386BSD 0.1 1992-07-28 [DOC]
360 4.4BSD Alpha 1992-07-07
361 BSD/386 0.9.3 1992-10-xx [BSDI]
362 first external gamma; G customers
363 BSD/386 0.9.4 1992-12-xx [BSDI]
364 would have been 1.0 except for request
365 for preliminary injunction
366 BSD/386 1.0 1993-03-xx [BSDI]
367 injunction denied; first official release
368 NetBSD 0.8 1993-04-20 [NBD]
369 4.4BSD 1993-06-01 [USE]
370 NetBSD 0.9 1993-08-23 [NBD]
371 FreeBSD 1.0 1993-11-01 [FBD]
372 FreeBSD 1.0.2 1993-11-14 [FBD]
373 supersedes 1.0 13 days after release.
374 BSD/386 1.1 1994-02-xx [BSDI]
375 4.4BSD Lite 1994-03-01 [USE]
376 FreeBSD 1.1 1994-05-07 [FBD]
377 FreeBSD 1.1.5 1994-06-30 [FBD]
378 FreeBSD 1.1.5.1 1994-07-05 [FBD]
379 supersedes 1.1.5 5 days after release.
380 NetBSD 1.0 1994-10-26 [NBD]
381 386BSD 1.0 1994-11-12 [USE]
382 FreeBSD 2.0 1994-11-23 [FBD]
383 BSD/OS 2.0 1995-01-xx [BSDI] 4.4 lite based
384 FreeBSD 2.0.5 1995-06-10 [FBD]
385 BSD/OS 2.0.1 1995-06-xx [BSDI]
386 4.4BSD Lite Release 2 1995-06-xx [44B]
387 the true final distribution from the CSRG
388 FreeBSD 2.1.0 1995-11-19 [FBD]
389 NetBSD 1.1 1995-11-26 [NBD]
390 BSD/OS 2.1 1996-01-xx [BSDI]
391 FreeBSD 2.1.5 1996-07-14 [FBD]
392 NetBSD 1.2 1996-10-04 [NBD]
393 OpenBSD 2.0 1996-10-18 [OBD]
394 FreeBSD 2.1.6 1996-11-16 [FBD]
395 FreeBSD 2.1.6.1 1996-11-25 [FBD] (sendmail security release)
397 FreeBSD 2.1.7 1997-02-20 [FBD]
398 BSD/OS 3.0 1997-02-xx [BSDI] 4.4 lite2 based
399 FreeBSD 2.2.0 1997-03-16 [FBD]
400 FreeBSD 2.2.1 1997-03-25 [FBD]
401 FreeBSD 2.2.2 1997-05-16 [FBD]
402 NetBSD 1.2.1 1997-05-20 [NBD] (patch release)
403 OpenBSD 2.1 1997-06-01 [OBD]
404 FreeBSD 2.2.5 1997-10-22 [FBD]
405 OpenBSD 2.2 1997-12-01 [OBD]
406 NetBSD 1.3 1998-01-04 [NBD]
407 FreeBSD 2.2.6 1998-03-25 [FBD]
408 NetBSD 1.3.1 1998-03-09 [NBD] (patch release)
409 BSD/OS 3.1 1998-03-xx [BSDI]
410 OpenBSD 2.3 1998-05-19 [OBD]
411 NetBSD 1.3.2 1998-05-29 [NBD] (patch release)
412 FreeBSD 2.2.7 1998-07-22 [FBD]
413 BSD/OS 4.0 1998-08-xx [BSDI]
414 2-lock MP support, ELF executables
415 FreeBSD 3.0 1998-10-16 [FBD]
416 FreeBSD-3.0 is a snapshot from -current,
417 while 3.1 and 3.2 are from 3.x-stable which
418 was branched quite some time after 3.0-release
419 FreeBSD 2.2.8 1998-11-29 [FBD]
420 OpenBSD 2.4 1998-12-01 [OBD]
421 NetBSD 1.3.3 1998-12-23 [NBD] (patch release)
422 FreeBSD 3.1 1999-02-15 [FBD]
423 BSD/OS 4.0.1 1999-03-xx [BSDI]
424 NetBSD 1.4 1999-05-12 [NBD]
425 FreeBSD 3.2 1999-05-17 [FBD]
426 OpenBSD 2.5 1999-05-19 [OBD]
427 NetBSD 1.4.1 1999-08-26 [NBD] (patch release)
428 FreeBSD 3.3 1999-09-17 [FBD]
429 OpenBSD 2.6 1999-12-01 [OBD]
430 FreeBSD 3.4 1999-12-20 [FBD]
431 BSD/OS 4.1 1999-12-xx [BSDI]
432 FreeBSD 4.0 2000-03-13 [FBD]
433 NetBSD 1.4.2 2000-03-19 [NBD] (patch release)
434 OpenBSD 2.7 2000-06-15 [OBD]
435 FreeBSD 3.5 2000-06-24 [FBD]
436 FreeBSD 4.1 2000-07-27 [FBD]
437 FreeBSD 3.5.1 2000-07-28 [FBD]
438 FreeBSD 4.1.1 2000-09-25 [FBD] (a network-only patch release)
439 FreeBSD 4.2 2000-11-21 [FBD]
440 NetBSD 1.4.3 2000-11-25 [NBD] (patch release)
441 BSD/OS 4.2 2000-11-29 [BSDI]
442 OpenBSD 2.8 2000-12-01 [OBD]
443 NetBSD 1.5 2000-12-06 [NBD]
444 Mac OS X 10.0 2001-03-24 [APL]
445 FreeBSD 4.3 2001-04-20 [FBD]
446 OpenBSD 2.9 2001-06-01 [OBD]
447 NetBSD 1.5.1 2001-07-11 [NBD] (patch release)
448 NetBSD 1.5.2 2001-09-13 [NBD] (patch release)
449 FreeBSD 4.4 2001-09-18 [FBD]
450 Mac OS X 10.1 2001-09-29 [APL]
451 OpenBSD 3.0 2001-12-01 [OBD]
452 FreeBSD 4.5 2002-01-29 [FBD]
453 BSD/OS 4.3 2002-03-14 [WRS]
454 OpenBSD 3.1 2002-05-19 [OBD]
455 FreeBSD 4.6 2002-06-15 [FBD]
456 NetBSD 1.5.3 2002-07-22 [NBD] (patch release)
457 FreeBSD 4.6.2 2002-08-15 [FBD] (patch release)
458 Mac OS X 10.2 2002-08-23 [APL]
459 NetBSD 1.6 2002-09-14 [NBD]
460 FreeBSD 4.7 2002-10-08 [FBD]
461 OpenBSD 3.2 2002-11-01 [OBD]
462 FreeBSD 5.0 2003-01-17 [FBD]
463 FreeBSD 5.0 is a separate branch off of
464 -current, similar to 3.0.
465 FreeBSD 4.8 2003-04-03 [FBD]
466 NetBSD 1.6.1 2003-04-21 [NBD] (patch release)
467 OpenBSD 3.3 2003-05-01 [OBD]
468 BSD/OS 5.0 2003-05-?? [WRS]
469 FreeBSD 5.1 2003-06-09 [FBD]
470 Mac OS X 10.3 2003-10-24 [APL]
471 FreeBSD 4.9 2003-10-28 [FBD]
472 BSD/OS 5.1 ISE 2003-10-?? [WRS] (final version)
473 OpenBSD 3.4 2003-11-01 [OBD]
474 FreeBSD 5.2 2004-01-12 [FBD]
475 FreeBSD 5.2.1 2004-02-22 [FBD] (patch release)
476 NetBSD 1.6.2 2004-03-01 [NBD] (patch release)
477 OpenBSD 3.5 2004-04-01 [OBD]
478 FreeBSD 4.10 2004-05-27 [FBD]
479 DragonFly 1.0 2004-07-12 [DFB]
480 OpenBSD 3.6 2004-10-29 [OBD]
481 FreeBSD 5.3 2004-11-06 [FBD]
482 NetBSD 2.0 2004-12-09 [NBD]
483 FreeBSD 4.11 2005-01-25 [FBD]
484 DragonFly 1.2.0 2005-04-08 [DFB]
485 NetBSD 2.0.2 2005-04-14 [NBD] (security/critical release)
486 Mac OS X 10.4 2005-04-29 [APL]
487 FreeBSD 5.4 2005-05-09 [FBD]
488 OpenBSD 3.7 2005-05-19 [OBD]
489 NetBSD 2.0.3 2005-10-31 [NBD] (security/critical release)
490 OpenBSD 3.8 2005-11-01 [OBD]
491 FreeBSD 6.0 2005-11-01 [FBD]
492 NetBSD 2.1 2005-11-02 [NBD]
493 NetBSD 3.0 2005-12-23 [NBD]
494 DragonFly 1.4.0 2006-01-08 [DFB]
495 OpenBSD 3.9 2006-05-01 [OBD]
496 FreeBSD 6.1 2006-05-08 [FBD]
497 FreeBSD 5.5 2006-05-25 [FBD]
498 NetBSD 3.0.1 2006-07-24 [NBD] (security/critical release)
499 DragonFly 1.6.0 2006-07-24 [DFB]
500 OpenBSD 4.0 2006-11-01 [OBD]
501 NetBSD 3.0.2 2006-11-04 [NBD] (security/critical release)
502 NetBSD 3.1 2006-11-04 [NBD]
503 FreeBSD 6.2 2007-01-15 [FBD]
504 DragonFly 1.8.0 2007-01-30 [DFB]
505 OpenBSD 4.1 2007-05-01 [OBD]
506 DragonFly 1.10.0 2007-08-06 [DFB]
507 Mac OS X 10.5 2007-10-26 [APL]
508 OpenBSD 4.2 2007-11-01 [OBD]
509 NetBSD 4.0 2007-12-19 [NBD]
510 FreeBSD 6.3 2008-01-18 [FBD]
511 DragonFly 1.12.0 2008-02-26 [DFB]
512 FreeBSD 7.0 2008-02-27 [FBD]
513 OpenBSD 4.3 2008-05-01 [OBD]
514 DragonFly 2.0.0 2008-07-21 [DFB]
515 OpenBSD 4.4 2008-11-01 [OBD]
516 FreeBSD 6.4 2008-11-28 [FBD]
517 FreeBSD 7.1 2009-01-04 [FBD]
518 DragonFly 2.2.0 2009-02-17 [DFB]
519 NetBSD 5.0 2009-04-29 [NBD]
520 OpenBSD 4.5 2009-05-01 [OBD]
521 FreeBSD 7.2 2009-05-04 [FBD]
522 Mac OS X 10.6 2009-06-08 [APL]
523 DragonFly 2.4.0 2009-09-16 [DFB]
524 OpenBSD 4.6 2009-10-18 [OBD]
525 FreeBSD 8.0 2009-11-26 [FBD]
526 FreeBSD 7.3 2010-03-23 [FBD]
527 DragonFly 2.6.0 2010-03-28 [DFB]
528 OpenBSD 4.7 2010-05-19 [OBD]
529 FreeBSD 8.1 2010-07-24 [FBD]
530 DragonFly 2.8.2 2010-10-30 [DFB]
531 OpenBSD 4.8 2010-11-01 [OBD]
532 NetBSD 5.1 2010-11-19 [NBD]
533 FreeBSD 7.4 2011-02-24 [FBD]
534 FreeBSD 8.2 2011-02-24 [FBD]
535 DragonFly 2.10.1 2011-04-26 [DFB]
536 OpenBSD 4.9 2011-05-01 [OBD]
539 ------------------------
541 Leffler, Samuel J., Marshall Kirk McKusick, Michael J Karels and John
542 Quarterman. The Design and Implementation of the 4.3BSD UNIX Operating
543 System. Reading, Mass. Addison-Wesley, 1989. ISBN 0-201-06196-1
545 Salus, Peter H. A quarter century of UNIX. Addison-Wesley Publishing
546 Company, Inc., 1994. ISBN 0-201-54777-5
548 McKusick, Marshall Kirk, Keith Bostic, Michael J Karels, and John
549 Quarterman. The Design and Implementation of the 4.4BSD Operating
550 System. Reading, Mass. Addison-Wesley, 1996. ISBN 0-201-54979-4
552 McKusick, Marshall Kirk, George Neville-Neil. The Design and
553 Implementation of the FreeBSD Operating System.
554 Addison-Wesley Professional, Published: Aug 2, 2004. ISBN 0-201-70245-2
556 Doug McIlroy. Research Unix Reader.
558 Michael G. Brown. The Role of BSD in the Development of Unix.
559 Presented to the Tasmanian Unix Special Interest Group of the
560 Australian Computer Society, Hobart, August 1993.
562 Peter H. Salus. Unix at 25. Byte Magazine, October 1994.
563 URL: http://www.byte.com/art/9410/sec8/art3.htm
565 Andreas Klemm, Lars Köller. If you're going to San Francisco ...
566 Die freien BSD-Varianten von Unix. c't April 1997, page 368ff.
568 BSD Release Announcements collection.
569 URL: http://www.FreeBSD.org/releases/
571 BSD Hypertext Man Pages
572 URL: http://www.FreeBSD.org/cgi/man.cgi
574 UNIX history graphing project
575 URL: http://minnie.tuhs.org/Unix_History/index.html
578 URL: http://www.levenez.com/unix/
580 James Howard: The BSD Family Tree
581 URL: http://ezine.daemonnews.org/200104/bsd_family.html
582 ("what are the differences between FreeBSD, NetBSD, and OpenBSD?")
588 Josh Gilliam for suggestions, bug fixes, and finding very old
589 original BSD announcements from Usenet or tapes.
591 Steven M. Schultz for providing 2.8BSD, 2.10BSD, 2.11BSD manual pages.
594 Copyright (c) 1997-2007 Wolfram Schneider <wosch@FreeBSD.ORG>
595 URL: http://cvsweb.freebsd.org/src/share/misc/bsd-family-tree
597 $FreeBSD: src/share/misc/bsd-family-tree,v 1.147 2011/05/22 14:03:30 uqs Exp $