<s>
The	O
TeachText	B-Operating_System
application	O
is	O
a	O
simple	B-Operating_System
text	I-Operating_System
editor	O
made	O
by	O
Apple	O
Computer	O
and	O
included	O
with	O
System	B-Operating_System
7.1	I-Operating_System
and	O
earlier	O
.	O
</s>
<s>
TeachText	B-Operating_System
was	O
one	O
of	O
the	O
only	O
applications	O
included	O
with	O
System	B-Operating_System
7	I-Operating_System
,	O
leading	O
to	O
its	O
frequent	O
role	O
as	O
the	O
application	O
to	O
open	O
"	O
ReadMe	O
"	O
files	O
.	O
</s>
<s>
It	O
was	O
named	O
"	O
TeachText	B-Operating_System
"	O
as	O
a	O
nod	O
to	O
this	O
role	O
in	O
tutorials	O
and	O
other	O
introductory	O
materials	O
.	O
</s>
<s>
TeachText	B-Operating_System
was	O
derived	O
from	O
the	O
Edit	B-Operating_System
application	I-Operating_System
,	O
which	O
was	O
a	O
simple	B-Operating_System
text	I-Operating_System
editor	O
for	O
the	O
early	O
pre-System	O
6	O
Apple	B-Device
Macintosh	I-Device
computers	O
.	O
</s>
<s>
Edit	B-Operating_System
was	O
included	O
with	O
early	O
versions	O
of	O
the	O
basic	O
system	O
software	O
to	O
demonstrate	O
the	O
use	O
of	O
the	O
Macintosh	B-Device
user	O
interface	O
,	O
and	O
as	O
the	O
primary	O
code	O
editing	O
tool	O
for	O
the	O
original	O
68000	O
Macintosh	B-Device
Development	O
System	O
.	O
</s>
<s>
While	O
Edit	B-Operating_System
was	O
a	O
tool	O
and	O
demonstration	O
program	O
for	O
developers	O
,	O
TeachText	B-Operating_System
was	O
used	O
mainly	O
by	O
users	O
to	O
display	O
ReadMe	O
documents	O
.	O
</s>
<s>
Since	O
the	O
first	O
Macintosh	B-Device
models	O
came	O
with	O
a	O
full-featured	O
word	B-General_Concept
processor	I-General_Concept
,	O
MacWrite	B-Operating_System
,	O
software	O
publishers	O
commonly	O
shipped	O
documentation	O
in	O
its	O
native	O
format	O
.	O
</s>
<s>
When	O
Apple	O
stopped	O
bundling	O
MacWrite	B-Operating_System
,	O
ownership	O
was	O
transferred	O
to	O
Claris	O
,	O
so	O
developers	O
could	O
not	O
distribute	O
it	O
on	O
their	O
programs	O
 '	O
installation	O
floppy	O
disks	O
.	O
</s>
<s>
Apple	O
supplied	O
TeachText	B-Operating_System
as	O
a	O
small	O
,	O
freely-distributable	O
program	O
to	O
address	O
this	O
need	O
.	O
</s>
<s>
TeachText	B-Operating_System
could	O
only	O
operate	O
on	O
a	O
single	O
document	O
at	O
a	O
time	O
and	O
supported	O
only	O
the	O
default	O
text	O
font	O
(	O
12-point	O
Geneva	O
at	O
the	O
time	O
)	O
in	O
the	O
MacRoman	O
encoding	O
,	O
with	O
formatting	O
such	O
as	O
bold	O
,	O
italic	O
and	O
underline	O
.	O
</s>
<s>
It	O
also	O
included	O
rudimentary	O
support	O
for	O
embedded	O
images	O
;	O
the	O
images	O
were	O
stored	O
in	O
PICT	B-Language
format	O
in	O
the	O
file	O
's	O
resource	B-Operating_System
fork	I-Operating_System
in	O
ascending	O
numbers	O
from	O
zero	O
,	O
instances	O
of	O
non-breaking	O
spaces	O
in	O
the	O
text	O
loaded	O
up	O
the	O
appropriately	O
numbered	O
image	O
,	O
the	O
first	O
instance	O
loading	O
image	O
"	O
0	O
"	O
,	O
the	O
second	O
space	O
loading	O
image	O
"	O
1	O
"	O
,	O
and	O
so	O
on	O
.	O
</s>
<s>
TeachText	B-Operating_System
was	O
automatically	O
associated	O
with	O
all	O
TEXT	O
type	O
codes	O
for	O
files	O
with	O
an	O
unknown	O
Creator	B-Operating_System
code	I-Operating_System
.	O
</s>
<s>
That	O
is	O
,	O
if	O
a	O
user	O
attempted	O
to	O
open	O
any	O
text	O
file	O
and	O
the	O
original	O
program	O
that	O
created	O
it	O
was	O
not	O
known	O
on	O
the	O
local	O
computer	O
,	O
TeachText	B-Operating_System
would	O
be	O
asked	O
to	O
open	O
the	O
file	O
in	O
its	O
place	O
.	O
</s>
<s>
In	O
this	O
respect	O
,	O
TeachText	B-Operating_System
was	O
the	O
"	O
default	O
editor	O
"	O
of	O
the	O
Mac	O
system	O
,	O
playing	O
a	O
role	O
similar	O
to	O
Notepad	B-Application
under	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
The	O
underlying	O
text	O
engine	O
was	O
the	O
TextEdit	B-Application
Manager	O
built	O
into	O
Mac	O
OS	O
.	O
</s>
<s>
TextEdit	B-Application
had	O
originally	O
been	O
written	O
to	O
support	O
very	O
small	O
runs	O
of	O
editable	O
text	O
,	O
like	O
those	O
found	O
in	O
Save	O
as	O
...	O
dialogs	O
and	O
similar	O
roles	O
.	O
</s>
<s>
TeachText	B-Operating_System
was	O
later	O
replaced	O
by	O
SimpleText	B-Operating_System
,	O
and	O
with	O
the	O
arrival	O
of	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
,	O
both	O
were	O
replaced	O
by	O
the	O
TextEdit	B-Application
application	I-Application
inherited	O
from	O
OPENSTEP	B-Operating_System
.	O
</s>
