<s>
Forward	O
compatibility	B-Device
or	O
upward	O
compatibility	B-Device
is	O
a	O
design	O
characteristic	O
that	O
allows	O
a	O
system	O
to	O
accept	O
input	B-General_Concept
intended	O
for	O
a	O
later	O
version	O
of	O
itself	O
.	O
</s>
<s>
A	O
standard	O
supports	O
forward	O
compatibility	B-Device
if	O
a	O
product	O
that	O
complies	O
with	O
earlier	O
versions	O
can	O
"	O
gracefully	O
"	O
process	O
input	B-General_Concept
designed	O
for	O
later	O
versions	O
of	O
the	O
standard	O
,	O
ignoring	O
new	O
parts	O
which	O
it	O
does	O
not	O
understand	O
.	O
</s>
<s>
Forward	O
compatibility	B-Device
for	O
the	O
older	O
system	O
usually	O
means	O
backward	B-General_Concept
compatibility	I-General_Concept
for	O
the	O
new	O
system	O
,	O
i.e.	O
</s>
<s>
the	O
ability	O
to	O
process	O
data	O
from	O
the	O
old	O
system	O
;	O
the	O
new	O
system	O
usually	O
has	O
full	O
compatibility	B-Device
with	O
the	O
older	O
one	O
,	O
by	O
being	O
able	O
to	O
both	O
process	O
and	O
generate	O
data	O
in	O
the	O
format	O
of	O
the	O
older	O
system	O
.	O
</s>
<s>
Forward	O
compatibility	B-Device
is	O
not	O
the	O
same	O
as	O
extensibility	B-Architecture
.	O
</s>
<s>
An	O
extensible	B-Architecture
design	O
makes	O
upgrading	O
easy	O
.	O
</s>
<s>
At	O
any	O
point	O
in	O
time	O
,	O
a	O
current	O
browser	O
is	O
forward	O
compatible	O
if	O
it	O
gracefully	O
accepts	O
a	O
newer	O
version	O
of	O
HTML	B-Language
.	O
</s>
<s>
Whereas	O
how	O
easily	O
the	O
browser	O
code	O
can	O
be	O
upgraded	O
to	O
process	O
the	O
newer	O
HTML	B-Language
determines	O
how	O
extensible	B-Architecture
it	O
is	O
.	O
</s>
<s>
The	O
introduction	O
of	O
FM	O
stereo	O
transmission	O
,	O
or	O
color	O
television	O
,	O
allowed	O
forward	O
compatibility	B-Device
,	O
since	O
monophonic	O
FM	O
radio	O
receivers	O
and	O
black-and-white	O
TV	O
sets	O
still	O
could	O
receive	O
a	O
signal	O
from	O
a	O
new	O
transmitter	O
.	O
</s>
<s>
It	O
also	O
allowed	O
backward	B-General_Concept
compatibility	I-General_Concept
since	O
new	O
receivers	O
could	O
receive	O
monophonic	O
or	O
black-and-white	O
signals	O
generated	O
by	O
old	O
transmitters	O
.	O
</s>
<s>
The	O
Game	B-Device
Boy	I-Device
is	O
able	O
to	O
play	O
certain	O
games	O
released	O
for	O
the	O
Game	B-Device
Boy	I-Device
Color	I-Device
.	O
</s>
<s>
These	O
games	O
utilize	O
the	O
same	O
cartridge	O
design	O
as	O
games	O
for	O
the	O
original	B-Device
Game	I-Device
Boy	I-Device
,	O
though	O
the	O
plastic	O
used	O
is	O
typically	O
black	O
rather	O
than	O
gray	O
and	O
feature	O
the	O
GBC	O
's	O
logo	O
on	O
the	O
label	O
and	O
packaging	O
;	O
Nintendo	O
officially	O
referred	O
to	O
such	O
titles	O
as	O
being	O
"	O
Dual	O
Mode	O
"	O
.	O
</s>
<s>
The	O
Leapster	B-Application
is	O
able	O
to	O
play	O
Leapster	B-Application
L-Max	O
games	O
.	O
</s>
<s>
The	O
Leapster	B-Application
L-Max	O
is	O
able	O
to	O
play	O
Leapster2	B-Application
games	O
.	O
</s>
<s>
The	O
original	B-Device
PlayStation	I-Device
is	O
compatible	O
with	O
the	O
DualShock	O
2	O
controller	O
.	O
</s>
<s>
Likewise	O
the	O
PlayStation	B-Operating_System
3	I-Operating_System
can	O
be	O
played	O
with	O
a	O
DualShock	O
4	O
controller	O
.	O
</s>
<s>
The	O
Neo	B-Device
Geo	I-Device
Pocket	I-Device
was	O
able	O
to	O
play	O
most	O
games	O
from	O
Neo	B-Application
Geo	I-Application
Pocket	I-Application
Color	I-Application
.	O
</s>
<s>
The	O
WonderSwan	B-Operating_System
is	O
able	O
to	O
play	O
some	O
WonderSwan	B-Operating_System
Color	I-Operating_System
games	O
.	O
</s>
<s>
The	B-Device
Xbox	I-Device
One	I-Device
can	O
use	O
the	O
controller	O
from	O
the	O
Xbox	B-Device
Series	I-Device
X	I-Device
and	I-Device
Xbox	I-Device
Series	I-Device
S	I-Device
,	O
and	O
in	O
contrast	O
,	O
an	O
Xbox	B-Device
One	I-Device
controller	O
will	O
work	O
on	O
the	O
Xbox	B-Device
Series	I-Device
X	I-Device
and	I-Device
Series	I-Device
S	I-Device
.	O
</s>
<s>
HTML	B-Language
is	O
designed	O
to	O
treat	O
all	O
tags	O
in	O
the	O
same	O
way	O
(	O
as	O
inert	O
,	O
unstyled	O
inline	O
elements	O
)	O
unless	O
their	O
appearance	O
or	O
behavior	O
is	O
overridden	O
;	O
either	O
by	O
the	O
browser	O
's	O
default	O
settings	O
,	O
or	O
by	O
scripts	O
or	O
styles	O
included	O
in	O
the	O
page	O
.	O
</s>
<s>
This	O
makes	O
most	O
new	O
features	O
degrade	B-General_Concept
gracefully	I-General_Concept
in	O
older	O
browsers	O
.	O
</s>
<s>
Because	O
there	O
is	O
no	O
mandatory	O
upgrade	O
of	O
computers	O
or	O
web	O
browsers	O
,	O
many	O
web	O
developers	O
use	O
a	O
graceful	B-General_Concept
degradation	I-General_Concept
or	O
progressive	O
enhancement	O
approach	O
,	O
attempting	O
to	O
make	O
newly-created	O
websites	O
that	O
are	O
usable	O
by	O
people	O
who	O
have	O
turned	O
off	O
Javascript	O
or	O
who	O
have	O
old	O
computers	O
or	O
old	O
web	O
browsers	O
or	O
on	O
a	O
slow	O
connection	O
,	O
yet	O
still	O
taking	O
advantage	O
of	O
faster	O
hardware	O
and	O
better	O
JavaScript	O
support	O
in	O
more	O
modern	O
web	O
browsers	O
,	O
when	O
available	O
.	O
</s>
<s>
Each	O
of	O
the	O
three	O
most	O
common	O
12cm	O
optical	B-Device
media	I-Device
formats	O
(	O
CD	O
,	O
DVD	O
,	O
and	O
Blu-ray	O
)	O
was	O
first	O
released	O
in	O
read-only	O
form	O
years	O
before	O
writable	O
forms	O
were	O
available	O
.	O
</s>
<s>
Within	O
each	O
format	O
,	O
there	O
is	O
both	O
forward	O
and	O
backward	B-General_Concept
compatibility	I-General_Concept
,	O
in	O
that	O
most	O
older	O
read-only	O
drives	O
and	O
players	O
can	O
read	O
(	O
but	O
not	O
write	O
)	O
writable	O
media	O
in	O
the	O
same	O
format	O
,	O
while	O
read/write	O
drives	O
can	O
read	O
(	O
but	O
not	O
write	O
)	O
old	O
read-only	O
media	O
.	O
</s>
<s>
There	O
is	O
no	O
forward	O
compatibility	B-Device
between	O
formats	O
;	O
a	O
CD	O
player	O
,	O
for	O
instance	O
,	O
ca	O
n't	O
read	O
a	O
DVD	O
(	O
a	O
newer	O
format	O
)	O
,	O
not	O
even	O
the	O
audio	O
tracks	O
.	O
</s>
<s>
There	O
may	O
be	O
backward	B-General_Concept
compatibility	I-General_Concept
for	O
better	O
marketability	O
(	O
such	O
as	O
a	O
DVD	O
player	O
playing	O
an	O
audio	O
CD	O
)	O
,	O
but	O
it	O
is	O
not	O
intrinsic	O
to	O
the	O
standards	O
.	O
</s>
<s>
In	O
some	O
cases	O
this	O
might	O
be	O
intentional	O
by	O
the	O
designers	O
as	O
a	O
form	O
of	O
vendor	O
lock-in	O
or	O
software	B-Error_Name
regression	I-Error_Name
.	O
</s>
<s>
Planned	O
obsolescence	O
is	O
a	O
type	O
of	O
upward	O
compatibility	B-Device
,	O
but	O
rather	O
than	O
adopting	O
a	O
policy	O
of	O
backwards	B-General_Concept
compatibility	I-General_Concept
,	O
companies	O
adopt	O
a	O
commercial	O
policy	O
of	O
backwards	O
incompatibility	O
so	O
that	O
newer	O
apps	O
require	O
newer	O
devices	O
.	O
</s>
