<s>
Cross-browser	B-Architecture
compatibility	I-Architecture
is	O
the	O
ability	O
of	O
a	O
website	O
or	O
web	B-Application
application	I-Application
to	O
function	O
across	O
different	O
browsers	B-Application
and	O
degrade	B-General_Concept
gracefully	I-General_Concept
when	O
browser	B-Application
features	O
are	O
absent	O
or	O
lacking	O
.	O
</s>
<s>
The	O
history	O
of	O
cross-browser	B-Architecture
is	O
involved	O
with	O
the	O
history	O
of	O
the	O
"	O
browser	B-Application
wars	I-Application
"	O
in	O
the	O
late	O
1990s	O
between	O
Netscape	B-Protocol
Navigator	I-Protocol
and	O
Microsoft	B-Application
Internet	I-Application
Explorer	I-Application
as	O
well	O
as	O
with	O
that	O
of	O
JavaScript	B-Language
and	O
JScript	B-Language
,	O
the	O
first	O
scripting	O
languages	O
to	O
be	O
implemented	O
in	O
the	O
web	B-Application
browsers	I-Application
.	O
</s>
<s>
Netscape	B-Protocol
Navigator	I-Protocol
was	O
the	O
most	O
widely	O
used	O
web	B-Application
browser	I-Application
at	O
that	O
time	O
and	O
Microsoft	O
had	O
licensed	O
Mosaic	B-Application
to	O
create	O
Internet	B-Application
Explorer	I-Application
1.0	O
.	O
</s>
<s>
New	O
versions	O
of	O
Netscape	B-Protocol
Navigator	I-Protocol
and	O
Internet	B-Application
Explorer	I-Application
were	O
released	O
at	O
a	O
rapid	O
pace	O
over	O
the	O
following	O
few	O
years	O
.	O
</s>
<s>
Due	O
to	O
the	O
intense	O
competition	O
in	O
the	O
web	B-Application
browser	I-Application
market	O
,	O
the	O
development	O
of	O
these	O
browsers	B-Application
was	O
fast-paced	O
and	O
new	O
features	O
were	O
added	O
without	O
any	O
coordination	O
between	O
vendors	O
.	O
</s>
<s>
The	O
introduction	O
of	O
new	O
features	O
often	O
took	O
priority	O
over	O
bug	O
fixes	O
,	O
resulting	O
in	O
unstable	O
browsers	B-Application
,	O
fickle	O
web	O
standards	O
compliance	O
,	O
frequent	O
crashes	O
and	O
many	O
security	O
holes	O
.	O
</s>
<s>
The	O
World	O
Wide	O
Web	O
Consortium	O
(	O
W3C	O
)	O
,	O
founded	O
in	O
1994	O
to	O
promote	O
open	O
standards	O
for	O
the	O
World	O
Wide	O
Web	O
,	O
pulled	O
Netscape	B-Protocol
and	O
Microsoft	O
together	O
with	O
other	O
companies	O
to	O
develop	O
a	O
standard	O
for	O
browser	B-Application
scripting	O
languages	O
called	O
ECMAScript	B-Language
.	O
</s>
<s>
Subsequent	O
releases	O
of	O
JavaScript	B-Language
and	O
JScript	B-Language
would	O
implement	O
the	O
ECMAScript	B-Language
standard	O
for	O
greater	O
cross-browser	B-Architecture
compatibility	I-Architecture
.	O
</s>
<s>
After	O
the	O
standardization	O
of	O
ECMAScript	B-Language
,	O
W3C	O
began	O
work	O
on	O
the	O
standardization	O
of	O
Document	B-General_Concept
Object	I-General_Concept
Model	I-General_Concept
(	O
DOM	B-General_Concept
)	O
,	O
which	O
is	O
a	O
way	O
of	O
representing	O
and	O
interacting	O
with	O
objects	O
in	O
HTML	B-Language
,	O
XHTML	B-Language
and	O
XML	B-Protocol
documents	I-Protocol
.	O
</s>
<s>
DOM	B-General_Concept
Level	O
0	O
and	O
DOM	B-General_Concept
Level	O
1	O
were	O
introduced	O
in	O
1996	O
and	O
1997	O
.	O
</s>
<s>
Only	O
limited	O
supports	O
of	O
these	O
were	O
implemented	O
by	O
the	O
browsers	B-Application
,	O
as	O
a	O
result	O
,	O
non-conformant	O
browsers	B-Application
such	O
as	O
Internet	O
Explorer	O
4.x	O
and	O
Netscape	B-Protocol
4.x	O
were	O
still	O
widely	O
used	O
as	O
late	O
as	O
2000	O
.	O
</s>
<s>
DOM	B-General_Concept
Standardization	O
became	O
popular	O
since	O
the	O
introduction	O
of	O
DOM	B-General_Concept
Level	O
2	O
,	O
which	O
was	O
published	O
in	O
2000	O
.	O
</s>
<s>
It	O
introduced	O
the	O
"	O
getElementById	B-General_Concept
"	O
function	O
as	O
well	O
as	O
an	O
event	O
model	O
and	O
support	O
for	O
XML	B-Protocol
namespaces	O
and	O
CSS	B-Language
.	O
</s>
<s>
DOM	B-General_Concept
Level	O
3	O
,	O
the	O
current	O
release	O
of	O
the	B-General_Concept
DOM	I-General_Concept
specification	O
,	O
published	O
in	O
April	O
2004	O
,	O
added	O
support	O
for	O
XPath	B-Language
and	O
keyboard	O
event	O
handling	O
,	O
as	O
well	O
as	O
an	O
interface	O
for	O
serializing	O
documents	O
as	O
XML	B-Protocol
.	O
</s>
<s>
By	O
2005	O
,	O
large	O
parts	O
of	O
W3C	O
DOM	B-General_Concept
were	O
well-supported	O
by	O
common	O
ECMAScript-enabled	O
browsers	B-Application
,	O
including	O
Microsoft	B-Application
Internet	I-Application
Explorer	I-Application
,	O
Opera	B-Application
,	O
Safari	B-Application
and	O
Gecko-based	O
browsers	B-Application
(	O
like	O
Firefox	B-Application
,	O
SeaMonkey	B-Language
and	O
Camino	B-Language
)	O
.	O
</s>
<s>
In	O
the	O
early	O
part	O
of	O
the	O
century	O
,	O
practices	O
such	O
as	O
browser	B-Protocol
sniffing	I-Protocol
were	O
deemed	O
unusable	O
for	O
cross-browser	B-Architecture
scripting	O
.	O
</s>
<s>
The	O
term	O
"	O
multi-browser	O
"	O
was	O
coined	O
to	O
describe	O
applications	O
that	O
relied	O
on	O
browser	B-Protocol
sniffing	I-Protocol
or	O
made	O
otherwise	O
invalid	O
assumptions	O
about	O
run-time	O
environments	O
,	O
which	O
at	O
the	O
time	O
were	O
almost	O
invariably	O
Web	B-Application
browsers	I-Application
.	O
</s>
<s>
The	O
term	O
"	O
cross-browser	B-Architecture
"	O
took	O
on	O
its	O
currently	O
accepted	O
meaning	O
at	O
this	O
time	O
,	O
as	O
applications	O
that	O
once	O
worked	O
in	O
Internet	B-Protocol
Explorer	I-Protocol
4	I-Protocol
and	O
Netscape	B-Protocol
Navigator	I-Protocol
4	O
and	O
had	O
since	O
become	O
unusable	O
in	O
modern	O
browsers	B-Application
could	O
not	O
reasonably	O
be	O
described	O
as	O
"	O
cross-browser	B-Architecture
"	O
.	O
</s>
<s>
Colloquially	O
,	O
such	O
multi-browser	O
applications	O
,	O
as	O
well	O
as	O
frameworks	O
and	O
libraries	O
,	O
are	O
still	O
referred	O
to	O
as	O
cross-browser	B-Architecture
.	O
</s>
