<s>
MacTCP	B-Operating_System
was	O
the	O
standard	O
TCP/IP	B-Protocol
implementation	O
for	O
the	O
classic	B-Application
Mac	I-Application
OS	I-Application
through	O
version	O
7.5.1	O
.	O
</s>
<s>
It	O
was	O
the	O
first	O
application-independent	O
implementation	O
of	O
a	O
TCP	B-Protocol
stack	I-Protocol
for	O
a	O
non-Unix	O
platform	O
and	O
predates	O
Winsock	B-Application
by	O
over	O
5	O
years	O
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
API	B-Application
was	O
unique	O
to	O
the	O
Mac	B-Application
OS	I-Application
,	O
and	O
at	O
least	O
one	O
developer	O
released	O
a	O
Berkeley	O
Sockets-derived	O
API	B-Application
to	O
make	O
porting	O
from	O
other	O
platforms	O
easier	O
.	O
</s>
<s>
MacTCP	B-Operating_System
was	O
not	O
included	O
free	O
with	O
Mac	B-Application
OS	I-Application
until	O
System	O
7.5	O
,	O
when	O
the	O
rising	O
popularity	O
of	O
the	O
Internet	O
made	O
it	O
a	O
necessity	O
.	O
</s>
<s>
Apple	O
replaced	O
it	O
in	O
1995	O
with	O
Open	B-Protocol
Transport	I-Protocol
,	O
which	O
had	O
an	O
improved	O
interface	O
for	O
user	O
configuration	O
,	O
although	O
MacTCP	B-Operating_System
remained	O
in	O
use	O
on	O
older	O
systems	O
due	O
to	O
its	O
generally	O
lower	O
system	O
requirements	O
.	O
</s>
