<s>
SGMLguid	B-General_Concept
,	O
also	O
known	O
as	O
"	O
CERN	O
SGML	B-Language
"	O
,	O
"	O
Waterloo	O
based	O
SGML	B-Language
"	O
,	O
and	O
"	O
Waterloo	O
SGML	B-Language
"	O
,	O
was	O
an	O
early	O
SGML	B-Language
application	O
developed	O
and	O
used	O
at	O
CERN	O
between	O
1986	O
and	O
1990	O
.	O
</s>
<s>
It	O
served	O
as	O
a	O
model	O
of	O
the	O
earliest	O
HTML	B-Language
specifications	O
.	O
</s>
<s>
Written	O
in	O
the	O
Rexx	B-Language
programming	I-Language
language	I-Language
,	O
installed	O
on	O
an	O
IBM	O
3090-200	O
mainframe	O
computer	O
,	O
and	O
running	O
on	O
the	O
VM/CMS	O
operating	O
system	O
,	O
the	O
system	O
stored	O
tens	O
of	O
thousands	O
of	O
documents	O
in	O
a	O
hierarchical	O
structure	O
.	O
</s>
<s>
CERNDOC	O
supported	O
two	O
markup	O
systems	O
:	O
a	O
GML	O
application	O
named	O
CERNPAPER	O
,	O
developed	O
locally	O
in	O
1985	O
,	O
and	O
a	O
SGML	B-Language
application	O
created	O
in	O
1986	O
by	O
Anders	O
Berglund	O
,	O
who	O
was	O
at	O
the	O
time	O
responsible	O
for	O
text	O
processing	O
in	O
the	O
CERN	O
data	O
handling	O
division	O
.	O
</s>
<s>
Berglund	O
mapped	O
a	O
Waterloo	O
SCRIPT	B-Application
macro	O
set	O
onto	O
SGML	B-Language
,	O
basing	O
his	O
application	O
on	O
the	O
document	O
type	O
defined	O
in	O
Annex	O
E	O
of	O
ISO	B-Language
8879	I-Language
and	O
on	O
AAP	B-General_Concept
DTD	I-General_Concept
,	O
the	O
American	O
Association	O
of	O
Publishers	O
 '	O
document	O
type	O
.	O
</s>
<s>
Prior	O
art	O
also	O
includes	O
the	O
IBM	B-Application
GML	I-Application
starter	O
set	O
.	O
</s>
<s>
In	O
1990	O
,	O
when	O
Eric	O
van	O
Herwijnen	O
acted	O
as	O
head	O
of	O
text	O
processing	O
in	O
the	O
CERN	O
Administrative	O
Services	O
Department	O
,	O
CERN	O
replaced	O
CERNDOC	O
with	O
the	O
IBM	O
Document	B-Application
Composition	I-Application
Facility	I-Application
(	O
DCF	O
)	O
,	O
thereby	O
obsoleting	O
both	O
CERNPAPER	O
and	O
SGMLguid	B-General_Concept
.	O
</s>
<s>
For	O
HTML	B-Language
,	O
Berners-Lee	O
adopted	O
SGML	B-Language
syntax	O
and	O
a	O
subset	O
of	O
the	O
tags	O
specified	O
in	O
CERN	O
's	O
SGMLguid	B-General_Concept
.	O
</s>
