<s>
Steel	B-Language
Bank	I-Language
Common	I-Language
Lisp	I-Language
(	O
SBCL	B-Language
)	O
is	O
a	O
free	B-Application
Common	B-Language
Lisp	I-Language
implementation	O
that	O
features	O
a	O
high-performance	O
native	O
compiler	B-Language
,	O
Unicode	O
support	O
and	O
threading	B-Operating_System
.	O
</s>
<s>
The	O
name	O
"	O
Steel	B-Language
Bank	I-Language
Common	I-Language
Lisp	I-Language
"	O
is	O
a	O
reference	O
to	O
Carnegie	B-Language
Mellon	I-Language
University	I-Language
Common	I-Language
Lisp	I-Language
from	O
which	O
SBCL	B-Language
forked	O
:	O
Andrew	O
Carnegie	O
made	O
his	O
fortune	O
in	O
the	O
steel	O
industry	O
and	O
Andrew	O
Mellon	O
was	O
a	O
successful	O
banker	O
.	O
</s>
<s>
SBCL	B-Language
descends	O
from	O
CMUCL	B-Language
(	O
created	O
at	O
Carnegie	O
Mellon	O
University	O
)	O
,	O
which	O
is	O
itself	O
descended	O
from	O
Spice	B-Language
Lisp	I-Language
,	O
including	O
early	O
implementations	O
for	O
the	O
Mach	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
on	O
the	O
IBM	B-Device
RT	I-Device
PC	I-Device
,	O
and	O
the	O
Three	O
Rivers	O
Computing	O
Corporation	O
PERQ	B-Device
computer	O
,	O
in	O
the	O
1980s	O
.	O
</s>
<s>
William	O
Newman	O
originally	O
announced	O
SBCL	B-Language
as	O
a	O
variant	O
of	O
CMUCL	B-Language
in	O
December	O
1999	O
.	O
</s>
<s>
The	O
main	O
point	O
of	O
divergence	O
at	O
the	O
time	O
was	O
a	O
clean	O
bootstrapping	B-Application
procedure	O
:	O
CMUCL	B-Language
requires	O
an	O
already	O
compiled	B-Language
executable	B-Application
binary	I-Application
of	O
itself	O
to	O
compile	B-Language
the	O
CMUCL	B-Language
source	O
code	O
,	O
whereas	O
SBCL	B-Language
supported	O
bootstrapping	B-Application
from	O
theoretically	O
any	O
ANSI-compliant	O
Common	B-Language
Lisp	I-Language
implementation	O
.	O
</s>
<s>
SBCL	B-Language
became	O
a	O
SourceForge	B-Application
project	O
in	O
September	O
2000	O
.	O
</s>
<s>
The	O
original	O
rationale	O
for	O
the	O
fork	B-Application
was	O
to	O
continue	O
the	O
initial	O
work	O
done	O
by	O
Newman	O
without	O
destabilizing	O
CMUCL	B-Language
which	O
was	O
at	O
the	O
time	O
already	O
a	O
mature	O
and	O
much-used	O
implementation	O
.	O
</s>
<s>
Since	O
then	O
SBCL	B-Language
has	O
attracted	O
several	O
developers	O
,	O
been	O
ported	O
to	O
multiple	O
hardware	O
architectures	O
and	O
operating	O
systems	O
,	O
and	O
undergone	O
many	O
changes	O
and	O
enhancements	O
:	O
while	O
it	O
has	O
dropped	O
support	O
for	O
several	O
CMUCL	B-Language
extensions	O
that	O
it	O
considers	O
beyond	O
the	O
scope	O
of	O
the	O
project	O
(	O
such	O
as	O
the	O
Motif	B-Application
interface	I-Application
)	O
it	O
has	O
also	O
developed	O
many	O
new	O
ones	O
,	O
including	O
native	O
threading	B-Operating_System
and	O
Unicode	O
support	O
.	O
</s>
<s>
William	O
Newman	O
stepped	O
down	O
as	O
project	O
administrator	O
for	O
SBCL	B-Language
in	O
April	O
2008	O
.	O
</s>
<s>
For	O
the	O
tenth	O
anniversary	O
of	O
SBCL	B-Language
,	O
a	O
Workshop	O
was	O
organized	O
.	O
</s>
<s>
Version	O
2.0.0	O
was	O
released	O
on	O
29	O
December	O
2019	O
for	O
the	O
20th	O
anniversary	O
of	O
SBCL	B-Language
,	O
with	O
no	O
major	O
breaking	O
changes	O
.	O
</s>
