<s>
Redline	B-Operating_System
is	O
a	O
video	O
game	O
for	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
developed	O
by	O
Jonas	O
Echterhoff	O
and	O
published	O
by	O
Ambrosia	O
Software	O
.	O
</s>
<s>
The	O
game	O
's	O
primary	O
features	O
are	O
its	O
ability	O
to	O
simulate	O
actual	O
racing	O
physics	O
,	O
online	O
play	O
,	O
and	O
support	O
for	O
the	O
addition	O
of	O
third	O
party	O
content	O
via	O
plug-ins	B-Application
.	O
</s>
<s>
Redline	B-Operating_System
also	O
has	O
several	O
modes	O
of	O
gameplay	O
for	O
those	O
who	O
prefer	O
arcade	O
style	O
physics	O
commonly	O
found	O
in	O
other	O
racing	O
games	O
.	O
</s>
<s>
The	O
game	O
is	O
now	O
currently	O
obsolete	O
and	O
an	O
error	O
message	O
will	O
be	O
displayed	O
upon	O
opening	O
the	O
application	O
as	O
of	O
OS	B-Operating_System
X	I-Operating_System
Snow	O
Leopard	O
and	O
above	O
.	O
</s>
<s>
However	O
,	O
a	O
fan-made	O
patch	O
allows	O
the	O
game	O
to	O
run	O
on	O
OS	B-Operating_System
X	I-Operating_System
Mavericks	I-Operating_System
and	O
above	O
,	O
but	O
in	O
single-player	O
modes	O
only	O
.	O
</s>
<s>
The	O
main	O
modes	O
of	O
gameplay	O
are	O
Quick	O
Race	O
and	O
Multiplayer	O
,	O
the	O
former	O
a	O
single	O
player	O
race	O
between	O
the	O
player	O
and	O
up	O
to	O
eleven	O
Artificial	B-Application
intelligence	I-Application
opponents	O
,	O
the	O
latter	O
a	O
race	O
of	O
up	O
to	O
twelve	O
human	O
or	O
A.I.	B-Application
</s>
<s>
Additionally	O
,	O
only	O
plug-in	B-Application
cars	O
and	O
tracks	O
that	O
are	O
had	O
by	O
all	O
players	O
may	O
be	O
used	O
.	O
</s>
<s>
To	O
simulate	O
a	O
rolling	O
start	O
,	O
the	O
player	O
is	O
placed	O
some	O
distance	O
away	O
from	O
the	O
starting	O
line	O
,	O
allowing	O
them	O
to	O
begin	O
the	O
first	O
lap	O
at	O
the	O
same	O
speed	O
as	O
a	O
normal	O
race	O
lap	O
(	O
versus	O
Redline	B-Operating_System
's	O
usual	O
standing	O
start	O
)	O
.	O
</s>
<s>
The	O
Redline	B-Operating_System
Racing	O
League	O
(	O
RRL	O
)	O
is	O
a	O
multi-race	O
Simulation	O
tournament	O
(	O
the	O
Summer	O
2007	O
season	O
was	O
20	O
races	O
)	O
held	O
over	O
the	O
course	O
of	O
about	O
3	O
months	O
.	O
</s>
<s>
Redline	B-Operating_System
has	O
a	O
now-inactive	O
community	O
of	O
dedicated	O
third	O
party	O
developers	O
who	O
once	O
constantly	O
released	O
new	O
cars	O
,	O
tracks	O
,	O
weather	O
settings	O
,	O
challenges	O
,	O
and	O
other	O
plug-ins	B-Application
for	O
the	O
game	O
.	O
</s>
<s>
Redline	B-Operating_System
has	O
received	O
positive	O
reviews	O
from	O
critics	O
,	O
including	O
an	O
8/10	O
from	O
Inside	B-Application
Mac	I-Application
Games	I-Application
.	O
</s>
<s>
Many	O
reviewers	O
stated	O
that	O
,	O
"	O
the	O
graphics	O
,	O
while	O
certainly	O
not	O
PGR3	B-Application
or	O
Gran	B-Device
Turismo	I-Device
4	I-Device
quality	O
,	O
are	O
completely	O
adequate	O
"	O
and	O
"	O
allow	O
Redline	B-Operating_System
to	O
run	O
on	O
almost	O
any	O
Mac.	O
"	O
</s>
