<s>
Fahrenheit	B-Library
was	O
an	O
effort	O
to	O
create	O
a	O
unified	O
high-level	O
API	B-General_Concept
for	O
3D	O
computer	O
graphics	O
to	O
unify	O
Direct3D	B-Application
and	O
OpenGL	B-Application
.	O
</s>
<s>
Direct3D	B-Application
and	O
OpenGL	B-Application
are	O
low-level	O
APIs	B-General_Concept
that	O
concentrate	O
primarily	O
on	O
the	O
rendering	O
steps	O
of	O
the	O
3D	B-General_Concept
rendering	I-General_Concept
pipeline	I-General_Concept
.	O
</s>
<s>
Programs	O
that	O
use	O
these	O
APIs	B-General_Concept
have	O
to	O
supply	O
a	O
considerable	O
amount	O
of	O
code	O
to	O
handle	O
the	O
rest	O
of	O
the	O
pipeline	O
.	O
</s>
<s>
Fahrenheit	B-Library
hoped	O
to	O
provide	O
a	O
single	O
API	B-General_Concept
that	O
would	O
do	O
most	O
of	O
this	O
work	O
,	O
and	O
then	O
call	O
either	O
Direct3D	B-Application
or	O
OpenGL	B-Application
for	O
the	O
last	O
steps	O
.	O
</s>
<s>
Much	O
of	O
the	O
original	O
Fahrenheit	B-Library
project	O
was	O
abandoned	O
,	O
and	O
Microsoft	O
and	O
SGI	O
eventually	O
gave	O
up	O
on	O
attempts	O
to	O
work	O
together	O
.	O
</s>
<s>
In	O
the	O
end	O
,	O
only	O
the	O
scene	B-Data_Structure
graph	I-Data_Structure
portion	O
of	O
the	O
Fahrenheit	B-Library
system	O
,	O
known	O
as	O
XSG	O
,	O
saw	O
a	O
release	O
and	O
was	O
discontinued	O
shortly	O
afterwards	O
.	O
</s>
<s>
In	O
the	O
1990s	O
SGI	O
's	O
OpenGL	B-Application
was	O
the	O
de	O
facto	O
standard	O
for	O
3D	O
computer	O
graphics	O
.	O
</s>
<s>
Prior	O
to	O
the	O
mid-90s	O
different	O
platforms	O
had	O
used	O
various	O
custom	O
solutions	O
,	O
but	O
SGI	O
's	O
power	O
in	O
the	O
graphics	O
market	O
,	O
combined	O
with	O
the	O
efforts	O
of	O
the	O
OpenGL	B-Application
Architecture	O
Review	O
Board	O
(	O
ARB	O
)	O
,	O
led	O
to	O
the	O
rapid	O
standardization	O
of	O
OpenGL	B-Application
across	O
the	O
majority	O
of	O
the	O
graphics	B-Device
workstation	I-Device
market	O
.	O
</s>
<s>
In	O
the	O
mid-1990s	O
,	O
Microsoft	O
licensed	O
OpenGL	B-Application
for	O
their	O
Windows	B-Device
NT	I-Device
operating	B-General_Concept
system	I-General_Concept
as	O
its	O
primary	O
3D	O
system	O
;	O
Microsoft	O
was	O
positioning	O
NT	O
as	O
a	O
workstation-class	O
system	O
,	O
and	O
OpenGL	B-Application
was	O
required	O
in	O
order	O
to	O
be	O
a	O
real	O
competitor	O
in	O
this	O
space	O
.	O
</s>
<s>
Initial	O
support	O
was	O
released	O
in	O
Windows	B-Device
NT	I-Device
Workstation	I-Device
version	O
3.5	O
in	O
1994	O
.	O
</s>
<s>
Confusing	O
matters	O
was	O
Microsoft	O
's	O
February	O
1995	O
purchase	O
of	O
RenderMorphics	B-Application
.	O
</s>
<s>
Their	O
Reality	B-Application
Lab	I-Application
product	O
was	O
a	O
3D	O
library	O
written	O
specifically	O
for	O
gaming	O
purposes	O
,	O
aimed	O
primarily	O
at	O
the	O
"	O
low	O
end	O
"	O
market	O
.	O
</s>
<s>
After	O
renaming	O
it	O
to	O
Direct3D	B-Application
3.0	I-Application
,	O
Microsoft	O
released	O
it	O
as	O
the	O
primary	O
3D	O
API	B-General_Concept
for	O
Windows	B-Application
95	I-Application
and	O
game	O
programming	O
.	O
</s>
<s>
This	O
sparked	O
off	O
a	O
massive	O
debate	O
,	O
both	O
within	O
Microsoft	O
and	O
outside	O
,	O
about	O
the	O
merits	O
of	O
the	O
two	O
APIs	B-General_Concept
and	O
whether	O
or	O
not	O
Direct3D	B-Application
should	O
be	O
promoted	O
.	O
</s>
<s>
Through	O
the	O
mid-90s	O
SGI	O
had	O
been	O
working	O
on	O
a	O
series	O
of	O
efforts	O
to	O
provide	O
a	O
higher	O
level	O
API	B-General_Concept
on	O
top	O
of	O
OpenGL	B-Application
to	O
make	O
programming	O
easier	O
.	O
</s>
<s>
By	O
1997	O
this	O
had	O
evolved	O
into	O
their	O
OpenGL++	B-Library
system	O
,	O
a	O
retained-mode	O
C++	B-Language
API	B-General_Concept
on	O
top	O
of	O
OpenGL	B-Application
.	O
</s>
<s>
They	O
proposed	O
that	O
a	O
modified	O
version	O
be	O
used	O
as	O
a	O
single	O
API	B-General_Concept
on	O
top	O
of	O
either	O
OpenGL	B-Application
or	O
a	O
new	O
high-performance	O
low-level	O
API	B-General_Concept
that	O
Microsoft	O
was	O
known	O
to	O
be	O
working	O
on	O
(	O
not	O
based	O
on	O
Reality	B-Application
Lab	I-Application
)	O
.	O
</s>
<s>
This	O
would	O
not	O
only	O
hide	O
the	O
implementation	O
details	O
and	O
make	O
the	O
OpenGL/DirectX	O
war	O
superfluous	O
,	O
but	O
at	O
the	O
same	O
time	O
offer	O
considerably	O
better	O
high-level	O
interfaces	O
for	O
a	O
more	O
robust	O
object	B-Language
oriented	I-Language
development	O
environment	O
.	O
</s>
<s>
The	O
OpenGL++	B-Library
effort	O
dragged	O
on	O
in	O
the	O
ARB	O
through	O
1997	O
.	O
</s>
<s>
A	O
joint	O
press	O
release	O
in	O
December	O
1997	O
,	O
followed	O
by	O
an	O
announcement	O
at	O
an	O
ARB	O
meeting	O
in	O
early	O
1998	O
by	O
SGI	O
,	O
announced	O
that	O
work	O
on	O
OpenGL++	B-Library
had	O
been	O
abandoned	O
and	O
SGI	O
had	O
partnered	O
with	O
Microsoft	O
to	O
produce	O
a	O
new	O
system	O
code-named	O
"	O
Fahrenheit	B-Library
"	O
.	O
</s>
<s>
SGI	O
was	O
to	O
provide	O
the	O
primary	O
"	O
mid-sized	O
"	O
API	B-General_Concept
used	O
in	O
most	O
applications	O
,	O
Fahrenheit	B-Library
Scene	B-Data_Structure
Graph	I-Data_Structure
,	O
as	O
well	O
as	O
a	O
modified	O
version	O
for	O
handling	O
very	O
large	O
models	O
from	O
CAD	B-Application
applications	O
,	O
Fahrenheit	B-Library
Large	O
Model	O
.	O
</s>
<s>
Microsoft	O
would	O
provide	O
a	O
new	O
low-level	O
rendering	O
engine	O
for	O
Windows	O
known	O
as	O
Fahrenheit	B-Library
Low	O
Level	O
,	O
essentially	O
a	O
replacement	O
for	O
the	O
Reality	O
Lab-based	O
version	O
of	O
Direct3D	B-Application
.	O
</s>
<s>
Fahrenheit	B-Library
became	O
the	O
primary	O
focus	O
of	O
development	O
at	O
SGI	O
.	O
</s>
<s>
Their	O
MIPS-based	O
workstations	B-Device
were	O
quickly	O
losing	O
the	O
performance	O
lead	O
they	O
had	O
in	O
the	O
early	O
1990s	O
,	O
and	O
the	O
company	O
was	O
in	O
serious	O
trouble	O
as	O
the	O
average	O
PC	O
slowly	O
but	O
surely	O
encroached	O
on	O
the	O
high-end	O
graphics	O
market	O
.	O
</s>
<s>
SGI	O
saw	O
Fahrenheit	B-Library
as	O
an	O
exit	O
strategy	O
;	O
once	O
complete	O
they	O
would	O
be	O
able	O
to	O
move	O
to	O
a	O
PC-based	O
lineup	O
while	O
still	O
offering	O
the	O
best	O
development	O
tools	O
for	O
a	O
now	O
universal	O
API	B-General_Concept
.	O
</s>
<s>
Although	O
no	O
porting	O
work	O
began	O
,	O
toolkits	O
like	O
Open	B-Application
Inventor	I-Application
and	O
OpenGL	B-Library
Performer	I-Library
were	O
intended	O
in	O
future	O
to	O
be	O
layered	O
on	O
Fahrenheit	B-Library
,	O
meaning	O
that	O
they	O
could	O
deliver	O
a	O
single	O
fully	O
functional	O
development	O
system	O
for	O
Fahrenheit	B-Library
when	O
it	O
shipped	O
,	O
supporting	O
both	O
their	O
existing	O
customers	O
as	O
well	O
as	O
new	O
ones	O
.	O
</s>
<s>
Without	O
Low	O
Level	O
,	O
Fahrenheit	B-Library
could	O
n't	O
be	O
delivered	O
on	O
Windows	O
,	O
and	O
the	O
project	O
stalled	O
.	O
</s>
<s>
Eventually	O
SGI	O
abandoned	O
work	O
on	O
Fahrenheit	B-Library
and	O
started	O
planning	O
other	O
Scene	B-Data_Structure
Graph	I-Data_Structure
products	O
which	O
became	O
the	O
last	O
in	O
a	O
series	O
of	O
such	O
projects	O
.	O
</s>
<s>
DirectX	O
had	O
become	O
the	O
primary	O
API	B-General_Concept
during	O
the	O
rise	O
of	O
3D	O
gaming	O
in	O
the	O
late	O
1990s	O
.	O
</s>
<s>
Microsoft	O
did	O
release	O
Fahrenheit	B-Library
Scene	B-Data_Structure
Graph	I-Data_Structure
as	O
XSG	O
the	O
same	O
year	O
,	O
but	O
did	O
so	O
with	O
a	O
note	O
saying	O
it	O
would	O
not	O
be	O
supported	O
.	O
</s>
<s>
No	O
new	O
versions	O
of	O
XSG	O
were	O
ever	O
released	O
,	O
and	O
all	O
of	O
the	O
pages	O
related	O
to	O
either	O
Fahrenheit	B-Library
or	O
XSG	O
on	O
both	O
the	O
Microsoft	O
and	O
SGI	O
web	O
pages	O
have	O
since	O
disappeared	O
.	O
</s>
<s>
Hardware	O
accelerated	O
OpenGL	B-Application
support	O
was	O
dropped	O
from	O
the	O
included	O
video	O
drivers	O
in	O
Windows	B-Application
XP	I-Application
,	O
although	O
most	O
video	O
card	O
manufacturers	O
deliver	O
their	O
own	O
implementations	O
.	O
</s>
<s>
As	O
compared	O
to	O
Open	B-Application
Inventor	I-Application
or	O
Iris	B-Library
Performer	I-Library
,	O
the	O
design	O
of	O
the	O
XSG	O
included	O
some	O
novel	O
ideas	O
.	O
</s>
<s>
The	O
composition	O
primitives	O
and	O
traversal	O
methods	O
allowed	O
applications	O
to	O
construct	O
scenes	O
in	O
a	O
manner	O
best	O
suited	O
to	O
the	O
structure	O
of	O
the	O
data	O
being	O
visualized	O
,	O
but	O
then	O
to	O
apply	O
a	O
scene	B-Data_Structure
graph	I-Data_Structure
optimizer	O
to	O
restructure	O
the	O
scene	O
for	O
more	O
efficient	O
rendering	O
without	O
changing	O
the	O
scene	O
's	O
appearance	O
.	O
</s>
<s>
Pipelined	O
rendering	O
allowed	O
a	O
multithreaded	O
application	O
to	O
construct	O
the	O
scene	O
,	O
cull	O
its	O
primitives	O
,	O
and	O
render	O
it	O
in	O
different	O
threads	O
(	O
borrowing	O
from	O
the	O
Performer	B-Library
app-cull-draw	O
pipeline	O
)	O
.	O
</s>
<s>
David	O
Blythe	O
,	O
the	O
primary	O
architect	O
of	O
Fahrenheit	B-Library
at	O
SGI	O
,	O
worked	O
at	O
Microsoft	O
on	O
DirectX	O
until	O
2010	O
.	O
</s>
