<s>
is	O
the	O
standard	O
English	O
language	O
spell	B-Application
checker	I-Application
for	O
Unix	B-Application
,	O
Plan	B-Operating_System
9	I-Operating_System
,	O
and	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
Appearing	O
in	O
Version	B-Operating_System
6	I-Operating_System
Unix	I-Operating_System
,	O
was	O
originally	O
written	O
by	O
Stephen	O
C	B-Language
.	O
Johnson	O
of	O
Bell	O
Labs	O
in	O
1975	O
.	O
</s>
<s>
Douglas	O
McIlroy	O
later	O
improved	O
its	O
accuracy	O
,	O
performance	O
,	O
and	O
memory	O
use	O
,	O
and	O
described	O
his	O
work	O
and	O
spell	B-Application
in	O
general	O
in	O
his	O
1982	O
paper	O
""	O
.	O
</s>
<s>
Spell	B-Application
has	O
a	O
simple	O
command-line	B-Application
interface	I-Application
:	O
It	O
goes	O
over	O
all	O
the	O
words	O
in	O
a	O
given	O
text	O
file	O
,	O
and	O
prints	O
a	O
sorted	O
list	O
of	O
unique	O
misspelled	O
words	O
in	O
that	O
file	O
.	O
</s>
<s>
In	O
1983	O
,	O
a	O
different	O
spell-checker	B-Application
,	O
(	O
the	O
interactive	O
spell-checker	B-Application
)	O
,	O
was	O
ported	O
to	O
Unix	B-Application
.	O
</s>
<s>
Since	O
then	O
,	O
the	O
original	O
Spell	B-Application
tool	O
has	O
been	O
mostly	O
considered	O
obsolete	O
.	O
</s>
<s>
Another	O
reason	O
Spell	B-Application
is	O
considered	O
obsolete	O
is	O
that	O
it	O
only	O
supports	O
the	O
English	O
language	O
.	O
</s>
<s>
Modern	O
spell-checkers	B-Application
for	O
Unix	B-Application
and	O
Linux	B-Application
systems	O
,	O
such	O
as	O
aspell	B-Language
,	O
MySpell	B-Application
and	O
hunspell	B-Application
,	O
support	O
a	O
multitude	O
of	O
different	O
languages	O
and	O
character	O
sets	O
.	O
</s>
<s>
The	O
Single	O
Unix	B-Application
Specification	O
has	O
officially	O
declared	O
Spell	B-Application
a	O
"	O
legacy	O
application	O
"	O
,	O
stating	O
that	O
this	O
was	O
done	O
"	O
because	O
there	O
is	O
no	O
known	O
technology	O
that	O
can	O
be	O
used	O
to	O
make	O
it	O
recognise	O
general	O
language	O
for	O
user-specified	O
input	O
without	O
providing	O
a	O
complete	O
dictionary	O
along	O
with	O
the	O
input	O
file.	O
"	O
</s>
<s>
Nevertheless	O
,	O
the	O
Single	O
Unix	B-Application
Specification	O
does	O
not	O
standardize	O
any	O
other	O
spell-checking	B-Application
utility	O
to	O
take	O
Spell	B-Application
's	O
place	O
.	O
</s>
<s>
Because	O
of	O
Spell	B-Application
's	O
problems	O
and	O
the	O
superiority	O
of	O
its	O
alternatives	O
,	O
a	O
free	B-Application
software	I-Application
version	O
of	O
McIlroy	O
's	O
has	O
never	O
been	O
written	O
.	O
</s>
<s>
Instead	O
,	O
in	O
1996	O
Thomas	O
Morgan	O
of	O
GNU	B-Operating_System
wrote	O
a	O
simple	O
wrapper	O
to	O
(	O
which	O
was	O
already	O
popular	O
at	O
the	O
time	O
)	O
to	O
replicate	O
spell	B-Application
's	O
original	O
behaviour	O
.	O
</s>
<s>
Many	O
Linux	B-Application
distributions	I-Application
include	O
this	O
GNU	B-Operating_System
,	O
or	O
an	O
even	O
simpler	O
shell	B-Language
script	I-Language
;	O
For	O
example	O
,	O
the	O
""	O
command	B-Application
in	O
Fedora	O
Linux	B-Application
simply	O
runs	O
,	O
as	O
:	O
</s>
