<s>
This	O
article	O
covers	O
the	O
evolution	O
of	O
time-sharing	B-General_Concept
systems	I-General_Concept
,	O
providing	O
links	O
to	O
major	O
early	O
time-sharing	B-General_Concept
operating	I-General_Concept
systems	I-General_Concept
,	O
showing	O
their	O
subsequent	O
evolution	O
.	O
</s>
<s>
Time-sharing	B-General_Concept
was	O
first	O
proposed	O
in	O
the	O
mid	O
-	O
to	O
late-1950s	O
and	O
first	O
implemented	O
in	O
the	O
early	O
1960s	O
.	O
</s>
<s>
The	O
concept	O
was	O
born	O
out	O
of	O
the	O
realization	O
that	O
a	O
single	O
expensive	O
computer	O
could	O
be	O
efficiently	O
utilized	O
if	O
a	O
multitasking	O
,	O
multiprogramming	O
operating	O
system	O
allowed	O
multiple	O
users	O
simultaneous	O
interactive	B-General_Concept
access	I-General_Concept
.	O
</s>
<s>
Each	O
user	O
would	O
use	O
their	O
own	O
computer	B-General_Concept
terminal	I-General_Concept
,	O
initially	O
electromechanical	O
teleprinters	O
such	O
as	O
the	O
Teletype	B-Application
Model	I-Application
33	I-Application
ASR	O
or	O
the	O
Friden	B-Application
Flexowriter	I-Application
;	O
from	O
about	O
1970	O
these	O
were	O
progressively	O
superseded	O
by	O
CRT-based	O
units	O
such	O
as	O
the	O
DEC	B-Application
VT05	I-Application
,	O
Datapoint	B-Device
2200	I-Device
and	O
Lear	O
Siegler	O
ADM-3A	B-Device
.	O
</s>
<s>
Terminals	O
were	O
initially	O
linked	O
to	O
a	O
nearby	O
computer	O
via	O
current	O
loop	O
or	O
serial	O
cables	O
,	O
by	O
conventional	O
telegraph	O
circuits	O
provided	O
by	O
PTTs	O
and	O
over	O
specialist	O
digital	O
leased	B-Architecture
lines	I-Architecture
such	O
T1	O
.	O
</s>
<s>
Modems	B-Application
such	O
as	O
the	O
Bell	O
103	O
and	O
successors	O
,	O
allowed	O
remote	O
and	O
higher-speed	O
use	O
over	O
the	O
analogue	O
voice	O
telephone	O
network	O
.	O
</s>
<s>
The	O
Cambridge	O
Multiple-Access	O
System	O
was	O
the	O
first	O
time-sharing	B-General_Concept
system	I-General_Concept
developed	O
outside	O
the	O
United	O
States	O
.	O
</s>
<s>
+	O
Important	O
time-sharing	B-General_Concept
systems	I-General_Concept
,	O
1960	O
–	O
1990	O
(	O
and	O
successors	O
)	O
;	O
listed	O
alphabetically	O
Influences	O
:	O
⇶	O
derivation	O
⇉	O
strong	O
influence	O
→	O
some	O
influence/precedence	O
System	O
Platform	O
Dates	O
in	O
use	O
Developer	O
Description	O
Influences	O
:	O
from	O
→	O
→	O
to	O
ACP	B-Application
S/360	B-Application
and	O
S/370	B-Device
1965	O
–	O
1979	O
IBM	O
High-performance	O
mainframe	O
transaction	O
platform	O
used	O
in	O
SABRE	B-Application
and	O
PARS	B-Application
⇶	O
TPF	B-Operating_System
⇶	O
z/TPF	B-Operating_System
APL	B-Language
(	O
"	O
A	B-Language
Programming	I-Language
Language	I-Language
,	O
"	O
also	O
"	O
Iverson	O
's	O
Language	O
"	O
)	O
System/360	B-Application
,	O
others	O
later	O
1964	O
–	O
present	O
Kenneth	O
Iverson	O
Mathematically-oriented	O
language	O
and	O
interactive	O
environment	O
,	O
noted	O
for	O
incredible	O
terseness	O
and	O
powerful	O
set	O
processing	O
operators	O
Berkeley	B-General_Concept
Timesharing	I-General_Concept
System	I-General_Concept
SDS	B-Device
940	I-Device
1964	O
–	O
1972	O
Project	O
Genie	O
Early	O
general-purpose	O
⇉	O
TENEX	B-Operating_System
Cambridge	O
Multiple-Access	O
System	O
Titan	B-Device
,	O
the	O
prototype	O
Atlas	B-Device
2	O
1967	O
–	O
1973	O
University	O
of	O
Cambridge	O
and	O
Ferranti	O
Multiple	O
Access	O
System	O
Project	O
MAC	O
⇶	O
⇶	O
UNIX	B-Application
CANDE	B-Operating_System
Burroughs	B-Device
Large	I-Device
Systems	I-Device
,	O
Burroughs	B-Language
Medium	I-Language
Systems	I-Language
1965	O
?	O
–	O
present	O
Burroughs	O
first	O
IDE	O
(	O
separate	O
evolution	O
)	O
CICS	B-Application
S/3x0	O
1969	O
–	O
present	O
IBM	O
Ubiquitous	O
mainframe	O
transaction	O
platform	O
;	O
often	O
used	O
with	O
IBM	B-Operating_System
3270	I-Operating_System
terminals	O
and	O
COBOL	B-Application
CP-40/CMS	B-Application
customized	O
S/360	B-Application
-40	O
1967	O
–	O
1972	O
?	O
</s>
<s>
IBM	O
's	O
Cambridge	O
Scientific	O
Center	O
First	O
implementation	O
of	O
full	B-Architecture
virtualization	I-Architecture
CTSS	B-Operating_System
→⇶	O
CP-67	B-Application
CP-67/CMS	B-Application
IBM	B-Device
System/360	I-Device
-67	I-Device
1967	O
–	O
1975	O
?	O
</s>
<s>
IBM	O
's	O
Cambridge	O
Scientific	O
Center	O
Influential	O
precursor	O
to	O
IBM	O
's	O
VM	B-Application
series	O
,	O
widely	O
distributed	O
as	O
open	B-License
source	I-License
CP-40	B-Application
⇶⇶	O
VP/CSS	B-Application
⇶	O
VM/370	B-Application
⇶	O
z/VM	B-Application
CTSS	B-Operating_System
(	O
"	O
Compatible	B-Operating_System
Time	I-Operating_System
Sharing	I-Operating_System
System	I-Operating_System
"	O
)	O
modified	O
IBM	B-Device
7094	I-Device
1961	O
–	O
1973	O
MIT	O
Computation	O
Center	O
First-generation	O
"	O
grandfather	O
"	O
of	O
time-sharing	B-General_Concept
systems	I-General_Concept
FMS	O
→	O
⇉	O
CP-40	B-Application
⇉	O
Multics	B-Application
⇉	O
ITS	B-Application
→	O
[	O
numerous	O
other	O
systems ]	O
DTSS	B-Operating_System
(	O
"	O
Dartmouth	B-Operating_System
Time	I-Operating_System
Sharing	I-Operating_System
System	I-Operating_System
"	O
)	O
GE	B-Device
200	I-Device
,	O
GE	B-Device
635	I-Device
,	O
Honeywell	B-Device
6000	I-Device
series	I-Device
1963	O
–	O
1999	O
Dartmouth	O
College	O
Early	O
time-sharing	B-General_Concept
system	I-General_Concept
running	O
Dartmouth	B-Language
BASIC	I-Language
and	O
other	O
tools	O
;	O
became	O
the	O
first	O
commercial	O
time-sharing	B-General_Concept
system	I-General_Concept
through	O
General	O
Electric	O
Information	O
Services	O
Division	O
FMS	O
→	O
⇉	O
CP-40	B-Application
⇉	O
Multics	B-Application
⇉	O
ITS	B-Application
→	O
[	O
numerous	O
other	O
systems ]	O
ITS	B-Application
(	O
"	O
Incompatible	B-Application
Timesharing	I-Application
System	I-Application
"	O
)	O
PDP-6	B-Device
,	O
PDP-10	B-Device
1967	O
–	O
1990	O
MIT	O
Artificial	O
Intelligence	O
Laboratory	O
"	O
Subversive	O
"	O
operating	O
system	O
developed	O
to	O
counter	O
direction	O
of	O
CTSS	B-Operating_System
.	O
</s>
<s>
The	O
original	O
platform	O
for	O
Macsyma	B-Language
,	O
EMACS	B-Application
and	O
other	O
important	O
applications	O
.	O
</s>
<s>
CTSS	B-Operating_System
→→	O
[	O
numerous	O
later	O
systems ]	O
JOSS	B-Language
(	O
"	O
JOHNNIAC	B-Language
Open	I-Language
Shop	I-Language
System	I-Language
"	O
)	O
JOHNNIAC	B-Device
,	O
PDP-6	B-Device
1963	O
–	O
1971	O
?	O
</s>
<s>
RAND	O
Corporation	O
Lightweight	O
,	O
interactive	B-General_Concept
computing	I-General_Concept
language	O
for	O
non-specialists	O
;	O
did	O
not	O
distinguish	O
operating	O
system	O
from	O
language	O
Highly	O
regarded	O
,	O
but	O
no	O
obvious	O
successors	O
Linux	B-Application
ubiquitous	O
1991	O
–	O
present	O
Linus	O
Torvalds	O
,	O
GNU	B-Application
project	I-Application
,	O
open	B-License
source	I-License
Operating	O
system	O
dominating	O
current	O
open	B-License
source	I-License
activities	O
UNIX	B-Application
⇉	O
minix	B-Operating_System
⇉→	O
[	O
numerous	O
other	O
systems ]	O
Microsoft	O
Windows( Windows	O
NT	O
4.0	O
Terminal	O
Server	O
Edition	O
)	O
x86	B-Operating_System
,	O
IA-64	B-General_Concept
,	O
others	O
1985	O
–	O
present	O
Microsoft	O
Ubiquitous	O
GUI	O
operating	O
system	O
MS-DOS	B-Application
⇉	O
OS/2	B-Application
⇉	O
VMS	B-Operating_System
⇉	O
MICA	B-Operating_System
⇉	O
Smalltalk	B-Application
⇉	O
MTS	O
(	O
Michigan	B-Application
Terminal	I-Application
System	I-Application
)	O
IBM	B-Device
S/360	I-Device
-67	I-Device
,	O
S/370	B-Device
1967	O
–	O
1999	O
University	O
of	O
Michigan	O
and	O
7	O
other	O
universities	O
First	O
(	O
Nov	O
.	O
1967	O
)	O
OS	O
to	O
use	O
the	O
virtual	B-Architecture
memory	I-Architecture
features	O
of	O
the	O
S/360	B-Device
-67	I-Device
.	O
</s>
<s>
Early	O
(	O
Sept	O
.	O
1968	O
)	O
S/360	B-Device
-67	I-Device
multiprocessor	B-Operating_System
support	O
.	O
</s>
<s>
CTSS	B-Operating_System
→	O
DTSS	B-Operating_System
→→	O
UNIX	B-Application
(	O
BSD	O
)	O
Multics	B-Application
GE	B-Device
645	I-Device
,	O
Honeywell	B-Device
6180	I-Device
1969	O
–	O
2000	O
Project	O
MAC	O
Rich	O
,	O
important	O
system	O
CTSS	B-Operating_System
⇉	O
⇉	O
UNIX	B-Application
⇉	O
[	O
many	O
other	O
systems ]	O
MVS/TSO	B-Application
System/370	B-Device
and	O
successors	O
1971	O
–	O
present	O
IBM	O
Probably	O
the	O
most	O
widely	O
used	O
version	O
of	O
TSO	O
,	O
extended	O
version	O
TSO/E	O
,	O
current	O
version	O
zOS-TSO	O
CTSS	B-Operating_System
→	O
TSS/360	B-Application
→	O
⇶	O
z/OS	B-Application
-TSO	I-Application
NOS	B-Operating_System
CDC	O
60-bit	O
platforms	O
1976-	O
??	O
</s>
<s>
Control	O
Data	O
Corporation	O
System	O
used	O
on	O
most	O
CDC	O
machines	O
"	O
A	O
partial	O
history	O
of	O
CDC	O
Operating	O
Systems	O
"	O
,	O
March	O
1976	O
MACE	O
→⇶	O
Kronos	B-Operating_System
⇉	O
NOS/BE	O
CDC	O
60-bit	O
platforms	O
1976-	O
??	O
</s>
<s>
Control	O
Data	O
Corporation	O
System	O
used	O
on	O
most	O
CDC	O
machines	O
COS	B-Operating_System
⇶	O
SCOPE	O
→⇶	O
ORVYL	B-Application
IBM	O
9672	O
1967-	O
??	O
</s>
<s>
Stanford	O
University	O
Early	O
time-sharing	B-General_Concept
system	I-General_Concept
;	O
source	O
of	O
the	O
WYLBUR	B-Application
editor	O
later	O
used	O
on	O
System/370	B-Device
platforms	O
OS/2	B-Application
(	O
as	O
Citrix	O
Multiuser	O
)	O
x86	B-Operating_System
1987	O
–	O
present	O
IBM/Microsoft	O
Joint	O
OS	O
effort	O
,	O
now	O
moribund	O
.	O
</s>
<s>
Still	O
available	O
as	O
eComStation	B-Device
and	O
ArcaOS	B-Device
.	O
</s>
<s>
DOS	B-Operating_System
⇶	O
Microsoft	B-Application
Windows	I-Application
⇉	O
OS/2	B-Application
⇶	O
eComStation	B-Device
⇶	O
ArcaOS	B-Device
5.0	I-Device
ROSCOE	O
System/360	B-Application
and	O
successors	O
1969	O
–	O
present	O
Applied	B-Operating_System
Data	I-Operating_System
Research	I-Operating_System
(	O
ADR	O
)	O
Early	O
time-sharing	B-General_Concept
editor	O
environment	O
,	O
often	O
used	O
as	O
an	O
alternative	O
to	O
TSOOral	O
History	O
of	O
Martin	O
A	O
.	O
Goetz	O
,	O
co-founder	O
of	O
Applied	B-Operating_System
Data	I-Operating_System
Research	I-Operating_System
(	O
ADR	O
)	O
,	O
interviewed	O
by	O
:	O
Burt	O
Grad	O
and	O
Luanne	O
Johnson	O
,	O
December	O
10	O
,	O
1985	O
at	O
Princeton	O
,	O
New	O
Jersey	O
,	O
Computer	O
History	O
Museum	O
Reference	O
No	O
.	O
</s>
<s>
X4579.2008	O
⇶	O
WRAP	O
RSTS/E	B-Operating_System
PDP-11	B-Device
1972	O
–	O
1992+	O
DEC	O
General-purpose	O
time-sharing	B-General_Concept
for	O
the	O
PDP-11	B-Device
RSX-11	B-Application
PDP-11	B-Device
1972-	O
??	O
</s>
<s>
DEC	O
Real-time	O
operating	O
system	O
for	O
the	O
PDP-11	B-Device
⇶	O
IAS	O
⇉	O
VMS	B-Operating_System
Smalltalk	B-Application
Xerox	B-Device
Alto	I-Device
,	O
later	O
made	O
portable	O
1972	O
–	O
present	O
Xerox	O
PARC	O
,	O
successors	O
Seminal	O
system	O
for	O
experimental	O
programming	O
,	O
responsible	O
for	O
many	O
modern	O
user	O
interface	O
concepts	O
⇉	O
Apple	B-Device
Lisa	I-Device
⇉	O
Apple	B-Device
Macintosh	I-Device
⇉	O
Microsoft	B-Application
Windows	I-Application
⇉	O
[	O
all	O
GUI	O
platforms ]	O
Stratus	B-General_Concept
VOS	I-General_Concept
i860	B-General_Concept
,	O
x86	B-Operating_System
,	O
PA-RISC	B-Device
,	O
68k	B-Device
1980	O
?	O
–	O
present	O
Stratus	B-General_Concept
Technologies	I-General_Concept
High-availability	B-General_Concept
fault-tolerant	B-General_Concept
transaction	B-General_Concept
processing	I-General_Concept
MULTICS	B-Application
⇉	O
TENEX	B-Operating_System
PDP-10	B-Device
1970	O
?	O
-	O
??	O
</s>
<s>
Bolt	O
Beranek	O
and	O
Newman	O
Influential	O
system	O
widely	O
used	O
at	O
research	O
and	O
government	O
sites	O
⇉	O
TOPS-20	B-Operating_System
⇉	O
VMS	B-Operating_System
TOPS-10	B-Operating_System
PDP-10	B-Device
1970	O
–	O
1988	O
?	O
</s>
<s>
(	O
as	O
TOPS-10	B-Operating_System
)	O
1964	O
–	O
1970	O
(	O
as	O
PDP-6	B-Device
Monitor	O
)	O
DEC	O
Widely	O
used	O
at	O
research	O
and	O
academic	O
sites	O
PDP-6	B-Device
Monitor	O
⇶→	O
TENEX	B-Operating_System
⇉	O
CP/M	B-Application
TOPS-20	B-Operating_System
DECsystem	B-Device
20	I-Device
1976-	O
??	O
</s>
<s>
DEC	O
Successor	O
to	O
TOPS-10	B-Operating_System
but	O
more	O
like	O
TENEX	B-Operating_System
TENEX	B-Operating_System
→	O
TOPS-10	B-Operating_System
→	O
TPF	B-Operating_System
S/3x0	O
1979	O
–	O
present	O
(	O
TPF	B-Operating_System
)	O
2005	O
–	O
present( 	O
z/TPF	B-Operating_System
)	O
IBM	O
High-performance	O
mainframe	O
transaction	O
platform	O
,	O
successor	O
to	O
ACP	B-Application
,	O
still	O
available	O
as	O
z/TPF	B-Operating_System
ACP	B-Application
⇶⇶	O
z/TPF	B-Operating_System
TSOS	B-Operating_System
RCA	B-Device
Spectra	I-Device
70	I-Device
and	O
successors	O
1968-today	O
RCA	O
Early	O
general	O
purpose	O
mainframe	O
OS	O
TSS-8	B-Operating_System
PDP-8	B-Device
1967	O
–	O
??	O
</s>
<s>
DEC	O
Simple	O
minicomputer	O
OS	O
→	O
RSTS/E	B-Operating_System
TSS/360TSS/370	O
IBM	B-Device
System/360	I-Device
-67	I-Device
and	O
successors	O
1967	O
–	O
1971	O
?	O
</s>
<s>
IBM	O
IBM	O
's	O
original	O
"	O
official	O
"	O
time-sharing	B-General_Concept
system	I-General_Concept
;	O
not	O
a	O
success	O
CTSS	B-Operating_System
→⇶	O
TSS/370	B-Application
Unisys/UNIVAC	O
EXEC	O
8	O
UNIVAC	O
1108	O
and	O
successors	O
1964	O
–	O
present	O
Sperry-Rand	O
et	O
al	O
.	O
</s>
<s>
Many	O
universities	O
and	O
government	O
agencies	O
were	O
early	O
users	O
EXEC	O
8	O
⇶	O
OS	O
1100	O
⇶	O
OS	B-Operating_System
2200	I-Operating_System
UNIX	B-Application
and	O
derivative	O
systems	O
ubiquitous	O
1969	O
–	O
present	O
Bell	O
Laboratories	O
and	O
successors	O
Ultimately	O
dominated	O
operating	O
system	O
thought	O
,	O
in	O
both	O
proprietary	O
and	O
open-source	B-License
descendants	O
Multics	B-Application
⇉	O
⇉	O
Linux	B-Application
VM/370VM/SEVM/SP	O
System/370	B-Device
and	O
successors	O
1972	O
–	O
19882000	O
–	O
present	O
(	O
z/VM	B-Application
)	O
IBM	O
Proprietary	O
reimplementation	O
of	O
CP/CMS	B-Application
,	O
still	O
available	O
as	O
z/VM	B-Application
CP-40	B-Application
⇶	O
CP-67	B-Application
⇶⇶	O
VM/ESA	B-Application
⇶	O
z/VM	B-Application
OpenVMS	B-Operating_System
VAX	B-Device
,	O
IA-64	B-General_Concept
,	O
DEC	B-Device
Alpha	I-Device
,	O
x86-64	B-Device
1977	O
–	O
present	O
DEC	O
Popular	O
DEC	O
operating	O
system	O
TENEX	B-Operating_System
→	O
RSX-11M	B-Application
⇉	O
⇉	O
MICA	B-Operating_System
⇉	O
Windows	B-Device
NT	I-Device
VP/CSS	B-Application
IBM	B-Device
System/360	I-Device
-67	I-Device
,	O
System/370	B-Device
and	O
successors	O
1968	O
–	O
1986	O
?	O
</s>
<s>
National	O
CSS	O
Proprietary	O
fork	O
of	O
CP/CMS	B-Application
developed	O
by	O
a	O
time-sharing	B-General_Concept
vendor	O
CP/CMS	B-Application
⇶	O
WYLBUR	B-Application
System/370	B-Device
and	O
successors	O
1967	O
–	O
2009	O
?	O
</s>
