<s>
SK8	B-Language
(	O
pronounced	O
"	O
skate	O
"	O
)	O
was	O
a	O
multimedia	O
authoring	O
environment	O
developed	O
in	O
Apple	O
's	O
Advanced	O
Technology	O
Group	O
from	O
1988	O
until	O
1997	O
.	O
</s>
<s>
It	O
was	O
described	O
as	O
"	O
HyperCard	B-Application
on	O
steroids	O
"	O
,	O
combining	O
a	O
version	O
of	O
HyperCard	B-Application
's	O
HyperTalk	B-Language
programming	I-Language
language	I-Language
with	O
a	O
modern	O
object-oriented	B-Language
application	O
platform	O
.	O
</s>
<s>
The	O
main	O
components	O
of	O
SK8	B-Language
included	O
the	O
object	B-Language
system	I-Language
,	O
the	O
programming	O
language	O
,	O
the	O
graphics	O
and	O
components	O
libraries	O
,	O
and	O
the	O
Project	O
Builder	O
,	O
an	O
integrated	B-Application
development	I-Application
environment	I-Application
.	O
</s>
<s>
For	O
much	O
of	O
its	O
history	O
,	O
SK8	B-Language
remained	O
a	O
research	O
project	O
,	O
and	O
inspired	O
a	O
number	O
of	O
other	O
Apple	O
projects	O
like	O
AppleScript	B-Application
,	O
as	O
well	O
as	O
seeing	O
use	O
as	O
a	O
prototyping	O
platform	O
.	O
</s>
<s>
Although	O
around	O
1993	O
a	O
team	O
was	O
assigned	O
by	O
the	O
Apple	O
Product	O
Division	O
to	O
release	O
a	O
SK8	B-Language
runtime	O
,	O
the	O
limitation	O
of	O
the	O
Mac	O
's	O
capabilities	O
as	O
well	O
as	O
the	O
shift	O
to	O
the	O
PowerPC	B-Architecture
chip	I-Architecture
made	O
such	O
a	O
large	O
project	O
intractable	O
.	O
</s>
<s>
With	O
the	O
bulk	O
of	O
the	O
original	O
vision	O
completed	O
and	O
no	O
easy	O
path	O
to	O
release	O
as	O
part	O
of	O
MacOS	B-Application
,	O
active	O
development	O
ended	O
in	O
1996	O
–	O
1997	O
,	O
and	O
the	O
Macintosh	B-Language
Common	I-Language
Lisp	I-Language
source	O
code	O
for	O
the	O
entire	O
project	O
was	O
released	O
to	O
the	O
public	O
in	O
1997	O
.	O
</s>
<s>
The	O
SK8	B-Language
project	O
was	O
created	O
by	O
Ruben	O
Kleiman	O
when	O
he	O
joined	O
Apple	O
in	O
1987	O
.	O
</s>
<s>
He	O
had	O
come	O
to	O
Apple	O
to	O
develop	O
a	O
flexible	O
,	O
object-oriented	B-Language
user	O
interface	O
and	O
multimedia	O
development	O
environment	O
.	O
</s>
<s>
Coincidentally	O
,	O
at	O
this	O
time	O
the	O
HyperCard	B-Application
,	O
with	O
its	O
direct	O
manipulation	O
interface	O
and	O
scripting	O
language	O
,	O
was	O
about	O
to	O
ship	O
.	O
</s>
<s>
While	O
HyperCard	B-Application
was	O
great	O
for	O
simple	O
applications	O
it	O
used	O
a	O
limited	O
interaction	O
model	O
–	O
the	O
"	O
stacks	O
"	O
of	O
cards	O
"	O
–	O
that	O
limited	O
its	O
potential	O
applicability	O
.	O
</s>
<s>
SK8	B-Language
attempted	O
to	O
extend	O
these	O
benefits	O
to	O
a	O
wider	O
programming	O
role	O
.	O
</s>
<s>
Early	O
work	O
on	O
what	O
would	O
become	O
SK8	B-Language
focused	O
on	O
infrastructure	O
rather	O
than	O
visual	O
programming	O
.	O
</s>
<s>
Kleiman	O
's	O
first	O
effort	O
was	O
a	O
dynamic	O
,	O
prototype-based	B-Application
object	I-Application
system	I-Application
,	O
MacFrames	O
,	O
a	O
frame/object	O
system	O
with	O
plug-ins	O
for	O
inference	O
engines	O
.	O
</s>
<s>
Through	O
preferences	O
settings	O
,	O
MacFrames	O
was	O
used	O
to	O
emulate	O
a	O
large	O
variety	O
of	O
object	B-Language
systems	I-Language
,	O
including	O
IntelliCorp	O
's	O
KEE	O
.	O
</s>
<s>
This	O
research	O
,	O
in	O
concert	O
with	O
users	O
developing	O
actual	O
applications	O
and	O
prototypes	O
at	O
Apple	O
,	O
yielded	O
the	O
object	O
model	O
used	O
in	O
SK8	B-Language
.	O
</s>
<s>
MacFrames	O
was	O
developed	O
in	O
Coral	O
Lisp	O
,	O
which	O
was	O
acquired	O
by	O
Apple	O
and	O
became	O
Macintosh	B-Language
Common	I-Language
Lisp	I-Language
.	O
</s>
<s>
The	O
Macintosh	O
at	O
that	O
time	O
had	O
no	O
generalized	O
inter-process	B-Operating_System
communication	I-Operating_System
(	O
IPC	O
)	O
system	O
.	O
</s>
<s>
Kleiman	O
created	O
an	O
IPC	O
init	B-Operating_System
for	O
the	O
Mac	O
to	O
allow	O
MacFrames	O
to	O
communicate	O
with	O
other	O
processes	O
,	O
in	O
particular	O
,	O
HyperCard	B-Application
.	O
</s>
<s>
This	O
allowed	O
HyperCard	B-Application
to	O
be	O
used	O
as	O
a	O
visual	O
programming	O
front-end	O
for	O
MacFrames	O
.	O
</s>
<s>
Another	O
goal	O
of	O
MacFrames	O
was	O
to	O
build	O
distributed	O
processing	O
right	O
into	O
the	O
object	B-Language
system	I-Language
.	O
</s>
<s>
The	O
SK8	B-Language
Project	O
Builder	O
was	O
created	O
to	O
provide	O
a	O
rich	O
set	O
of	O
direct	O
manipulation	O
tools	O
,	O
including	O
tools	O
for	O
building	O
interactive	O
controls	O
and	O
general	O
but	O
non-invasive	O
glueing	O
.	O
</s>
<s>
The	O
first	O
version	O
of	O
the	O
SK8	B-Language
graphics	O
system	O
was	O
designed	O
to	O
extend	O
HyperCard	B-Application
,	O
allowing	O
cards	O
to	O
have	O
multiple	O
layers	O
rather	O
than	O
a	O
single	O
"	O
background	O
"	O
template	O
.	O
</s>
<s>
The	O
SK8	B-Language
system	O
was	O
initially	O
programmed	O
in	O
Lisp	O
.	O
</s>
<s>
As	O
part	O
of	O
a	O
wider	O
effort	O
to	O
modernize	O
the	O
MacOS	B-Application
,	O
a	O
new	O
unified	O
scripting	O
language	O
was	O
desired	O
.	O
</s>
<s>
In	O
1989	O
Kleiman	O
joined	O
David	O
Canfield	O
Smith	O
and	O
Larry	O
Tesler	O
to	O
design	O
and	O
implement	O
the	O
first	O
version	O
of	O
AppleScript	B-Application
.	O
</s>
<s>
This	O
version	O
of	O
AppleScript	B-Application
used	O
SK8	B-Language
objects	O
,	O
and	O
two	O
later	O
the	O
Apple	O
Product	O
Division	O
re-implemented	O
AppleScript	B-Application
using	O
AppleEvents	B-Operating_System
as	O
the	O
glue	O
for	O
communicating	O
with	O
AppleScript	B-Application
objects	O
.	O
</s>
<s>
A	O
number	O
of	O
researchers	O
in	O
the	O
Advanced	O
Technology	O
Group	O
began	O
to	O
use	O
SK8	B-Language
for	O
their	O
projects	O
.	O
</s>
<s>
The	O
system	O
was	O
used	O
to	O
develop	O
prototypes	O
for	O
Newton	B-Device
,	O
QuickTime	O
interfaces	O
,	O
interprocess	B-Operating_System
communication	I-Operating_System
,	O
and	O
was	O
used	O
to	O
prototype	O
many	O
titles	O
,	O
including	O
Stagecraft	O
,	O
a	O
learning	O
tool	O
for	O
children	O
.	O
</s>
<s>
For	O
performance	O
reasons	O
,	O
in	O
1992	O
and	O
1993	O
SK8	B-Language
was	O
re-implemented	O
from	O
the	O
ground	O
up	O
.	O
</s>
<s>
Working	O
at	O
Apple	O
's	O
Cambridge	O
Research	O
Center	O
,	O
the	O
Macintosh	B-Language
Common	I-Language
Lisp	I-Language
object	B-Application
store	I-Application
was	O
isolated	O
and	O
directly	O
hooked	O
into	O
SK8	B-Language
's	O
store	O
.	O
</s>
<s>
The	O
SK8	B-Language
system	O
includes	O
the	O
object	B-Language
system	I-Language
,	O
the	O
graphics	O
and	O
component	O
objects	O
,	O
the	O
SK8Script	O
language	O
,	O
and	O
the	O
Project	O
Builder	O
environment	O
.	O
</s>
<s>
The	O
SK8	B-Language
object	B-Language
system	I-Language
was	O
,	O
like	O
JavaScript	B-Language
,	O
prototype-based	B-Application
,	O
but	O
unlike	O
JavaScript	B-Language
,	O
object	O
properties	O
were	O
themselves	O
objects	O
.	O
</s>
<s>
Until	O
1989	O
,	O
SK8	B-Language
's	O
scripting	O
language	O
was	O
Lisp	O
.	O
</s>
<s>
This	O
changed	O
to	O
SK8Script	O
,	O
which	O
was	O
heavily	O
influenced	O
by	O
HyperTalk	B-Language
(	O
HT	O
)	O
.	O
</s>
<s>
Many	O
of	O
the	O
differences	O
between	O
SK8Script	O
and	O
HyperTalk	B-Language
can	O
be	O
considered	O
to	O
be	O
generalization	O
of	O
HT	O
concepts	O
,	O
removing	O
tight	O
integration	O
with	O
particular	O
objects	O
in	O
the	O
HyperCard	B-Application
universe	O
and	O
replacing	O
them	O
with	O
generalized	O
syntax	O
that	O
could	O
interact	O
with	O
any	O
object	O
.	O
</s>
<s>
SK8	B-Language
's	O
universe	O
was	O
made	O
up	O
of	O
a	O
multimedia-oriented	O
system	O
using	O
Actors	O
on	O
a	O
Stage	O
.	O
</s>
<s>
Actors	O
were	O
any	O
objects	O
that	O
were	O
based	O
on	O
the	O
prototype	O
Actor	O
object	O
,	O
which	O
contained	O
the	O
basic	O
framework	O
needed	O
to	O
provide	O
2D	O
graphics	O
support	O
-	O
the	O
location	O
and	O
size	O
of	O
the	O
object	O
for	O
instance	B-Application
.	O
</s>
<s>
In	O
SK8	B-Language
,	O
a	O
traditional	O
window	O
was	O
an	O
object	O
like	O
any	O
other	O
graphics	O
object	O
.	O
</s>
<s>
All	O
SK8	B-Language
Actors	O
could	O
contain	O
other	O
actors	O
.	O
</s>
<s>
For	O
instance	B-Application
,	O
the	O
BevelRenderer	O
could	O
be	O
used	O
to	O
bevel	O
the	O
edges	O
around	O
an	O
Actor	O
,	O
producing	O
an	O
effect	O
like	O
Windows	O
3.x	O
controls	O
or	O
the	O
title	O
bar	O
in	O
NeXTSTEP	B-Application
.	O
</s>
<s>
These	O
include	O
libraries	O
,	O
user-created	O
functions	O
and	O
methods	B-Language
,	O
variables	O
,	O
and	O
so	O
forth	O
.	O
</s>
<s>
The	O
Object	O
Editor	O
that	O
appeared	O
listed	O
the	O
object	O
's	O
"	O
properties	O
"	O
(	O
instance	B-Application
and	O
class	B-Application
variables	I-Application
)	O
in	O
one	O
pane	O
,	O
and	O
it	O
's	O
"	O
handlers	O
"	O
(	O
methods	B-Language
)	O
in	O
another	O
.	O
</s>
<s>
SK8	B-Language
did	O
not	O
have	O
traditional	O
"	O
screens	O
"	O
;	O
it	O
used	O
an	O
invisible	O
"	O
Stage	O
"	O
object	O
that	O
served	O
as	O
the	O
background	O
for	O
managing	O
events	O
and	O
visual	O
objects	O
.	O
</s>
<s>
SK8	B-Language
did	O
,	O
however	O
,	O
include	O
a	O
system	O
for	O
editing	O
and	O
programming	O
complete	O
menu	O
bars	O
,	O
a	O
feature	O
that	O
HyperCard	B-Application
lacked	O
.	O
</s>
<s>
Another	O
oft-requested	O
feature	O
from	O
HyperCard	B-Application
was	O
a	O
media	O
editor	O
,	O
which	O
allowed	O
Macintosh	O
resources	O
to	O
be	O
moved	O
in	O
and	O
out	O
of	O
the	O
project	O
.	O
</s>
<s>
SK8	B-Language
built	O
this	O
functionality	O
into	O
the	O
IDE	O
.	O
</s>
<s>
SK8Script	O
offered	O
a	O
system	O
for	O
calling	O
in	O
and	O
out	O
of	O
operating	B-General_Concept
system	I-General_Concept
functions	O
,	O
allowing	O
it	O
to	O
more	O
directly	O
interact	O
with	O
the	O
Macintosh	B-Device
Toolbox	I-Device
.	O
</s>
<s>
In	O
HyperCard	B-Application
,	O
interacting	O
with	O
arbitrary	O
Toolbox	O
code	O
was	O
handled	O
through	O
custom	O
code	O
resources	O
known	O
as	O
XCMDs	O
and	O
XFCNs	B-Language
which	O
encapsulated	O
the	O
functionality	O
in	O
a	O
black	B-Device
box	I-Device
.	O
</s>
<s>
Under	O
SK8	B-Language
,	O
SK8Script	O
could	O
interact	O
directly	O
with	O
the	O
encapsulated	O
code	O
,	O
setting	O
variables	O
,	O
calling	O
functions	O
and	O
returning	O
results	O
.	O
</s>
