<s>
Think	B-Operating_System
C	I-Operating_System
(	O
stylized	O
as	O
THINK	B-Operating_System
C	I-Operating_System
;	O
formerly	O
Lightspeed	B-Operating_System
C	I-Operating_System
)	O
is	O
an	O
extension	O
of	O
the	O
C	B-Language
programming	I-Language
language	I-Language
for	O
the	O
classic	B-Application
Mac	I-Application
OS	I-Application
developed	O
by	O
Think	B-Operating_System
Technologies	I-Operating_System
,	O
released	O
first	O
in	O
mid-1986	O
.	O
</s>
<s>
Versions	O
3	O
and	O
later	O
were	O
essentially	O
a	O
subset	O
of	O
C++	B-Language
and	O
supported	O
basic	O
object-oriented	B-Language
programming	I-Language
(	O
OOP	O
)	O
concepts	O
such	O
as	O
single	O
inheritance	O
,	O
and	O
extensions	O
to	O
the	O
C	B-Language
standard	O
that	O
conformed	O
more	O
closely	O
to	O
the	O
needs	O
of	O
Mac	B-Application
OS	I-Application
programming	O
.	O
</s>
<s>
After	O
version	O
6	O
,	O
the	O
OOP	O
facilities	O
were	O
expanded	O
to	O
a	O
full	O
C++	B-Language
implementation	B-Application
,	O
and	O
the	O
product	O
was	O
rebranded	O
Symantec	O
C++	B-Language
starting	O
version	O
7	O
,	O
then	O
under	O
development	O
by	O
different	O
authors	O
.	O
</s>
<s>
The	O
long-awaited	O
version	O
8	O
brought	O
support	O
for	O
compiling	B-Language
to	O
PowerPC	B-Architecture
.	O
</s>
<s>
Think	B-Operating_System
C	I-Operating_System
,	O
and	O
later	O
Symantec	O
C++	B-Language
,	O
featured	O
a	O
class	B-Application
library	I-Application
and	O
framework	O
for	O
Mac	O
programming	O
called	O
the	O
Think	O
Class	B-Application
Library	I-Application
(	O
TCL	O
)	O
,	O
which	O
was	O
used	O
extensively	O
for	O
Macintosh	O
application	O
development	O
.	O
</s>
<s>
The	O
Lightspeed	O
and	O
Think	B-Operating_System
C	I-Operating_System
integrated	B-Application
development	I-Application
environment	I-Application
(	O
IDE	O
)	O
influenced	O
other	O
such	O
environments	O
,	O
though	O
considered	O
not	O
as	O
advanced	O
as	O
that	O
belonging	O
to	O
Think	O
Pascal	O
,	O
its	O
sister	O
language	O
product	O
.	O
</s>
<s>
It	O
was	O
considered	O
the	O
standard	O
environment	O
when	O
Macintosh	B-Operating_System
Programmer	I-Operating_System
's	I-Operating_System
Workshop	I-Operating_System
(	O
MPW	O
)	O
was	O
considered	O
an	O
overpriced	O
niche	O
product	O
,	O
and	O
most	O
Macintosh	O
products	O
were	O
developed	O
in	O
it	O
for	O
many	O
years	O
.	O
</s>
<s>
This	O
changed	O
with	O
transition	O
of	O
the	O
Mac	O
from	O
the	O
Motorola	B-Device
68000	I-Device
(	O
68K	B-Device
)	O
to	O
the	O
PowerPC	B-Architecture
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
(	O
CPU	O
)	O
.	O
</s>
<s>
Symantec	O
was	O
roughly	O
a	O
year	O
late	O
in	O
delivering	O
a	O
version	O
for	O
PowerPC	B-Architecture
,	O
and	O
was	O
widely	O
seen	O
as	O
having	O
fallen	O
behind	O
,	O
and	O
competitor	O
Metrowerks	O
 '	O
product	O
CodeWarrior	B-Operating_System
took	O
control	O
of	O
the	O
market	O
.	O
</s>
<s>
Despite	O
the	O
decline	O
in	O
popularity	O
of	O
their	O
IDE	O
,	O
Symantec	O
was	O
eventually	O
chosen	O
by	O
Apple	O
to	O
provide	O
next-generation	O
C/C	O
++	O
compilers	B-Language
for	O
MPW	O
in	O
the	O
form	O
of	O
Sc/Scpp	O
for	O
68K	B-Device
alongside	O
MrC/MrCpp	O
for	O
PowerPC	B-Architecture
.	O
</s>
<s>
These	O
remained	O
Apple	O
's	O
standard	O
compilers	B-Language
until	O
the	O
arrival	O
of	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
replaced	O
them	O
with	O
the	O
GNU	B-Application
Compiler	I-Application
Collection	I-Application
(	O
GCC	B-Application
)	O
.	O
</s>
<s>
Bruce	O
F	O
.	O
Webster	O
of	O
BYTE	O
named	O
Lightspeed	B-Operating_System
C	I-Operating_System
product	O
of	O
the	O
month	O
for	O
September	O
1986	O
.	O
</s>
<s>
While	O
criticizing	O
the	O
documentation	O
as	O
its	O
"	O
single	O
greatest	O
weakness	O
"	O
,	O
Webster	O
stated	O
that	O
Lightspeed	B-Operating_System
C	I-Operating_System
would	O
be	O
the	O
choice	O
if	O
he	O
had	O
to	O
select	O
one	O
compiler	B-Language
for	O
the	O
Macintosh	O
.	O
</s>
<s>
BYTE	O
in	O
1989	O
listed	O
Lightspeed	B-Operating_System
C	I-Operating_System
as	O
among	O
the	O
"	O
Distinction	O
"	O
winners	O
of	O
the	O
Byte	O
Awards	O
,	O
stating	O
that	O
it	O
"	O
wins	O
our	O
respect	O
because	O
of	O
its	O
powerful	O
features	O
and	O
low	O
price	O
"	O
.	O
</s>
<s>
THINK	B-Operating_System
C	I-Operating_System
5.0	O
obtained	O
in	O
4	O
(	O
out	O
5	O
)	O
rating	O
in	O
July	O
1992	O
issue	O
of	O
Macworld	O
,	O
praising	O
a	O
fast	O
compilation	B-Language
and	O
an	O
outstanding	O
development	O
environment	O
,	O
despite	O
an	O
insufficient	O
documentation	O
.	O
</s>
<s>
Symantec	O
C++	B-Language
8.0	O
obtained	O
a	O
3	O
(	O
out	O
5	O
)	O
rating	O
in	O
July	O
1995	O
issue	O
of	O
Macworld	O
,	O
comparing	O
favourably	O
the	O
speed	O
of	O
its	O
PowerPC	B-Architecture
compiled	B-Language
code	O
with	O
that	O
of	O
CodeWarrior	B-Operating_System
at	O
the	O
time	O
,	O
but	O
noting	O
how	O
delayed	O
the	O
product	O
has	O
been	O
and	O
its	O
heavy	O
requirement	O
on	O
resources	O
.	O
</s>
