1950 : The history of computer operating systems starts in this year, with simple schemes for running batch programs(running programs in groups these prog will not interact with user) efficiently, minimizing idle time between programs.

1960’s : Interactive use of systems started to gain ground. Not only interactive use, but having several people use the same computer at the same time(noting but multi user), from different terminals. Such systems were called time-sharing systems and were quite a challenge to implement compared to the batch systems.

1965’s : There were many attempts at building good time-sharing systems. Some of these were university research projects, others were commercial ones. One such project was Multics, which was quite innovative at the time. It had, for example, a hierarchical file system, something taken for granted in modern operating systems. This multics was the project of combined effort of Bell Lab’s, MIT,GE. The Multics project did not, however, progress very well. It took years longer to complete the anticipated and never got a significant share of the operating system market. One of the participants, Bell Labs, withdrew from the project. The Bell Labs people who were involved then made their own operating system and called it as Unix.

1969 : First UNIX 1 was released.

1970-1989 : So many flavers of unix came at this time depending on the lack of feature’s in previous systems up to unix 7 was released in this time.

1990 : By this time, Unix had a strong position in the server market and was especially strong in universities. Most universities had Unix systems and computer science students were exposed to them. Many of them wanted to run Unix on their own computers as well. Unfortunately, by that time, Unix had become commercial and rather expensive. About the only cheap option was Minix, a limited Unix-like system written by Andrew Tanenbaum for teaching purpose. There was also 386BSD, a precursor NetBSD, FreeBSD, and OpenBSD, but that wasn’t mature yet, and required higher end hardware than many had at home.

Into this scene came Linux, in October, 1991. Linus Torvalds, the author, had used Unix at the University of Helsinki, and wanted something similar on his PC at home. Since the commercial alternatives were way too expensive, he started out with Minix, but wanted something better and soon started to write his own operating system. After its first release, it soon attracted the attention of several other hackers. While Linux initially was not really useful except as a toy, it soon gathered enough features to be interesting even for people uninterested in operating system development.


first mail from linus to hacker community

From: [email protected] (Linus Benedict Torvalds)
Newsgroups: comp.os.minix
Subject: What would you like to see most in minix?
Summary: small poll for my new operating system
Message-ID: <[email protected]>
Date: 25 Aug 91 20:57:08 GMT
Organization: University of Helsinki

Hello everybody out there using minix -
I’m doing a (free) operating system (just a hobby, won’t be big and
professional like gnu) for 386(486) AT clones. This has been brewing
since april, and is starting to get ready.I’d like any feedback on
things people like/dislike in minix, as my OS resembles it somewhat
(same physical layout of the file-system(due to practical reasons)
among other things). I’ve currently ported bash(1.08) and gcc(1.40),and
things seem to work.This implies that I’ll get something practical within a
few months, and I’d like to know what features most people would want. Any
suggestions are welcome, but I won’t promise I’ll implement them :-)
Linus ([email protected])
PS. Yes – it’s free of any minix code, and it has a multi-threaded fs.
It is NOT protable (uses 386 task switching etc), and it probably never
will support anything other than AT-harddisks, as that’s
all I have :-(.


Second mail to community:

From: [email protected] (Linus Benedict Torvalds)
Newsgroups: comp.os.minix
Subject: Free minix-like kernel sources for 386-AT
Message-ID: <[email protected]>
Date: 5 Oct 91 05:41:06 GMT
Organization: University of Helsinki
Do you pine for the nice days of minix-1.1, when men were men and wrote their own device drivers?
Are you without a nice project and just dying to cut your teeth on a OS you can try to modify for your
needs? Are you finding it frustrating when everything works on minix? No more all-nighters to get a nifty program working? Then this post might be just for you :-)
As I mentioned a month(?)ago, I’m working on a free version of a minix-lookalike for AT-386 computers. It has
finally reached the stage where it’s even usable (though may not be depending on
what you want), and I am willing to put out the sources for wider distribution. It is just version 0.02 (+1 (very
small) patch already), but I’ve successfully run bash/gcc/gnu-make/gnu-sed/compress etc under it.
Sources for this pet project of mine can be found at nic.funet.fi (128.214.6.100) in the directory /pub/OS/Linux.
The directory also contains some README-file and a couple of binaries to work under linux
(bash, update and gcc, what more can you ask for :-). Full kernel source is provided, as no minix code has been
used. Library sources are only partially free, so that cannot be distributed currently. The system is able to compile
“as-is” and has been known to work. Heh. Sources to the binaries (bash and gcc) can be found at the
same place in /pub/gnu.


Linux itself is only the kernel of an operating system. The kernel is the part that makes all other programs run. It implements multitasking, and manages hardware devices, and generally enables applications to do their thing. All the programs that the user (or system administrator) actually interacts with are run on top of the kernel. Some of these are essential : for example, a command line interpreter (or shell), which is used both interactively and to write shell scripts (corresponding to .BAT files). Linus did not write these programs himself, and used existing free versions instead. This reduced greatly the amount of work he had to do to get a working environment. In fact, he often changed the kernel to make it easier to get the existing programs to run on Linux, instead of the other way around.

Most of the critically important syste
m software, including the C compiler, came from the Free Software Foundation’s GNU project. Started in 1984, the GNU project aims to develop an entire Unix-like operating system that is completely free. To credit them, many people like to refer to a Linux system as a GNU/Linux system. (GNU has their own kernel as well).

During 1992 and 1993, the Linux kernel gathered all the necessary features it required to work as a replacement for Unix workstations, including TCP/IP networking and a graphical windowing system (the X Window System). Linux also received plenty of industry attention, and several small companies were started to develop and distribute Linux. Dozens of user groups were founded, and the Linux Journal magazine started to appear in early 1994.

Version 1.0 of the Linux kernel was released in March 1994. Since then, the kernel has gone through many development cycles, each culminating in a stable version. Each development cycle has taken a year or three, and has involved redesigning and rewriting large parts of the kernel to deal with changes in hardware (for example, new ways to connect peripherals, such as USB) and to meet increased speed requirements as people apply Linux to larger and larger systems (or smaller and smaller ones : embedded Linux is becoming a hot topic). Now the latest version of linux is 2.6.33.3


Soon Linus faced some confrontation from none other than Andrew Tanenbaum, the great teacher who wrote MINIX. In a post to Linus, Tanenbaum commented:

“I still maintain the point that designing a monolithic kernel in 1991 is a fundamental error. Be thankful you are not my student. You would not get a high grade for such a design :-)”
(Andrew Tanenbaum to Linus Torvalds)

Linus later admitted that it was the worst point of his development of Linux. Tanenbaum was certainly the famous professor, and anything he said certainly mattered. But he was wrong with Linux, for Linus was one stubborn guy who won’t admit defeat. Tanenbaum also remarked that : “Linux is obsolete”. Now was the turn for the new Linux generation. Backed by the strong Linux community, Linus gave a reply to Tanenbaum which seems to be most fitting:

Your job is being a professor and researcher: That’s one hell of a good excuse for some of the brain-damages of minix.
(Linus Torvalds to Andrew Tanenbaum)

And work went on. Soon more than a hundred people joined the Linux camp. Then thousands. Then hundreds of thousands. This was no longer a hackers toy. Powered by a plethora of programs from the GNU project, Linux was ready for the actual showdown. It was licensed under GNU General Public License, thus ensuring that the source codes will be free for all to copy, study and to change. Students and computer programmers grabbed it.
Soon, commercial vendors moved in. Linux itself was, and is free. What the vendors did was to compile up various software and gather them in a distributable format, more like the other operating systems with which people were more familiar. Red Hat , Caldera, and some other companies gained substantial amount of response from the users worldwide. While these were commercial ventures, dedicated computer programmers created their very own volunteer-based distribution, the famed Debian. With the new Graphical User Interfaces (like X-window System, )the Linux distributions became very popular.

Meanwhile, there were amazing things happening with Linux. Besides the PC, Linux was ported to many different platforms. Linux was tweaked to run 3Com’s handheld PalmPilot computer. Clustering technology enabled large number of Linux machines to be combined into a single computing entity, a parallel computer. In April 1996, researchers at Los Alamos National Laboratory used Linux to run 68 PCs as a single parallel processing machine to simulate atomic shock waves. But unlike other Supercomputers costing a fortune, it was rather cheap. The do-it-yourself supercomputer cost only $152,000, including labor (connecting the 68 PCs with cables)-about one tenth the price of a comparable commercial machine. It reached a peak speed of 19 billion calculations per second, making it the 315th most powerful supercomputer in the world. And it was a robust one too. Three months later it still didn’t have to be rebooted.


A Beaming Linus Today
The best thing about Linux today is the fanatic following it commands. Whenever a new piece of hardware is out, Linux kernel is tweaked to take advantage of it. For example, within weeks after the introduction of Intel Xeon® Microprocessor, Linux kernel was tweaked and was ready for it. It has also been adapted for use in Alpha, Mac, PowerPC, and even for palmtops, a feat which is hardly matched by any other operating system. And it continues its journey into the new millennium, with the same enthusiasm that started one fine day back in 1991.

Patricia Miranda Torvalds
Linus in 2002
As for Linus, he remains a simple man. Unlike Bill Gates, he is not a billionaire. Having completed studies, he moved to USA and landed a job at Transmeta Corporation. After conducting a top-secret research and development project, Transmeta launched the Crusoeâ„¢ processor. Linus was an active member of the research team. Recently married to Tove, he is the proud father of a girl, Patricia Miranda Torvalds. But he remains as the world’s most favorite and most famous programmer to this d
ate. Revered by Computer communities worldwide, Linus is by far the most popular programmer on this planet.


Addtional info related to OS’s:

Different types of unix’s

1BSD
2BSD
3BSD
4BSD
4.4BSD Lite 1
4.4BSD Lite 2
386 BSD
Acorn RISC iX
Acorn RISC Unix
AIX
AIX PS/2
AIX/370
AIX/6000
AIX/ESA
AIX/RT
AMiX
AOS Lite
AOS Reno
ArchBSD
ASV
Atari Unix
A/UX
BOS
BRL Unix
BSD Net/1
BSD Net/2
BSD/386
BSD/OS
CB Unix
Chorus
Chorus/MiX
Coherent
CTIX
CXOs
Darwin
Debian GNU/Hurd
DEC OSF/1 ACP
DesktopBSD
Digital Unix
DragonFly BSD
Dynix
Dynix/ptx
ekkoBSD
Eunice
FireFly BSD
FreeBSD
FreeDarwin
GNU
GNU-Darwin
Gnuppix GNU/Hurd-L4
HPBSD
HP-UX
HP-UX BLS
IBM AOS
IBM IX/370
Interactive 386/ix
Interactive IS
IRIS GL2
IRIX
Linux
Lites
LSX
Mac OS X
Mac OS X Server
Mach
MERT
MicroBSD
Mini Unix
Minix
Minix-VMD
MIPS OS RISC/os
MirBSD
Mk Linux
Monterey
more/BSD
mt Xinu
MVS/ESA OpenEdition
NetBSD
NeXTSTEP
NonStop-UX
Open Desktop
Open UNIX
OpenBSD
OpenDarwin
OpenServer
OpenSolaris
OPENSTEP
OS/390 OpenEdition
OS/390 Unix
OSF/1
PC-BSD
PC/IX
Plan 9
Plurix
PWB
PWB/UNIX
QNX
QNX RTOS
QNX/Neutrino
QUNIX
ReliantUnix
Rhapsody
RISC iX
RT
SCO UNIX
SCO UnixWare
SCO Xenix
SCO Xenix System V/386
Security-Enhanced Linux
Silver OS
Sinix
Sinix ReliantUnix
Solaris
SPIX
SunOS
Triance OS
Tru64 Unix
Trusted IRIX/B
Trusted Solaris
Trusted Xenix
TS
Tunis
UCLA Locus
UCLA Secure Unix
Ultrix
Ultrix 32M
Ultrix-11
Unicos
Unicos/mk
Unicos/mp
Unicox-max
UNICS
UniSoft UniPlus new
UNIX 32V
UNIX Interactive
UNIX System III
UNIX System IV
UNIX System V
UNIX System V Release 2
UNIX System V Release 3
UNIX System V Release 4
UNIX System V/286
UNIX System V/386
UNIX Time-Sharing System
UnixWare
UNSW
USG
Venix
Xenix OS
Xinu
xMach
z/OS Unix System Services
Here is now some unixes that are not [yet] in my chart. Some web sites have listed them, like this site or this site. If you want to find more unixes, try Google :-)
ABCenix
ACIX
AD
Altos System V
ARIX
AurOS
BOS/X
C Executive
CLIX
Consensys Unix
Concentrix
ConvexOS
CPIX
Cromix
CX/UX
DC/OSx
Dell Unix
DG/UX
DISTRIX
DNIX
DomainOS
DRM System
DTIX
DVIX
ENIX
EP/IX
Esix SVR4
Eurix
FOR:PRO
FreeMiNT
FTX
Genix
HCR
Helios
HEP-UPX
HI-UX
IDRIS
INOS
LSX
LynxOS
MachTen
MacMach
MAXION/OS
MCS
Micronix
Microport SVR4
MicroPort Unix
Mimosnew
MMOS
MP-RAS UNIX
MST UNIX
Mulplix
Munix
NachOS
NCR Unix
NDIX
News-OS
NUXI
Oasis
ONIX
OPUS
OS 9
OS/MP
OSx
PCUNIX
PNX
QNIX
Regulus
RT/EMT
RTUX
SORIX
SOX
Sphinx
SPP-UX
Stellix
SUNIX
Super-UX
System B
Thix
TI System V
TNIX
Topix
TOS
Tropix
UHC Unix
Umax
Uniq
Unisis
Unity
UNOS
UTEK
UTS
UTX/32S
UX
UXP/DS
UZIX
VM/IX
VOLVIX
Xoftnix
Zeus

home page’s of different people who are resposiable for development of OS(unix and linux):

Brian Kernighan

http://cm.bell-labs.com/cm/cs/who/bwk/index.html

Dennis Ritchie

http://cm.bell-labs.com/cm/cs/who/dmr/index.html

Ken Thompson

http://plan9.bell-labs.com/who/ken/

The above three are responsable for unix first version.

Different types of Linux’s

The below site will give u different types of linux’s

The below guy responsable for linux develepment

Linus Torvalds

http://www.cs.helsinki.fi/u/torvalds/

And last but not least see the link below

http://www.catb.org/~esr/faqs/linus/

Q & A

1. When is first UNIX introduced?
Ans : 1969.

2. What is the present version of RedHat Enterprice Linux (by april 2007)?
Ans : RHEL5.

3. What is the present version of linux kernel (by april 2007)?
Ans : Precent version of linux kernel is 2.6.20.7.

4. What is the kernel type used bye linux?
Ans : Modular kernel (i will explain this in comming class ie in 133 classes).

5. State some Unix flavers you know?
Ans : Free BSD, NetBSD, OpenBSD, HP Unix(from HP), Solaries (from Sun micro systems).

6. State some Linux flavers you know?
Ans : RHEL, Fedora, CentOS, Ubuntu, Lindows(which have features of linux and MS window’s), Suse, Debain etc.

yle="font-family:verdana;">7. What is the main difference between fedora and RHEl?
Ans : a.RedHat will give support to only for RHEL but not for Fedora with some charge.

b. Fedora is a open source no help is provided by RedHat user group’s will provide help for this Fedora.
c. For every 2 years RHEL will be released where as Fedora is for very 6 months.
8. What is the different OS released from RedHat in the devision of RHEL side?
Ans : a. RedHat Desktop
b. RedHat Enterprice server
c. RedHat Advanced Server
d.RedHat work station.
9. What is the difference between Uinx and Linux?
a. unix is monolithic kernel where as linux uses modular kernel.
b. some commands will differ
c. unix is commersial where as linux is free
d. linux support different hardware you can install linux on notebook too.
10.What is the difference between linux and window’s?
Ans : The given below link is enough
http://www.michaelhorowitz.com/Linux.vs.Windows.html