<s>
Prograph	B-Language
is	O
a	O
visual	B-Language
,	O
object-oriented	B-Language
,	O
dataflow	B-Application
,	O
multiparadigm	O
programming	O
language	O
that	O
uses	O
iconic	O
symbols	O
to	O
represent	O
actions	O
to	O
be	O
taken	O
on	O
data	O
.	O
</s>
<s>
Commercial	O
Prograph	B-Language
software	O
development	O
environments	O
such	O
as	O
Prograph	B-Language
Classic	O
and	O
Prograph	B-Language
CPX	I-Language
were	O
available	O
for	O
the	O
Apple	B-Device
Macintosh	I-Device
and	O
Windows	B-Application
platforms	O
for	O
many	O
years	O
but	O
were	O
eventually	O
withdrawn	O
from	O
the	O
market	O
in	O
the	O
late	O
1990s	O
.	O
</s>
<s>
Support	O
for	O
the	O
Prograph	B-Language
language	O
on	O
macOS	B-Application
has	O
recently	O
reappeared	O
with	O
the	O
release	O
of	O
the	O
Marten	O
software	O
development	O
environment	O
.	O
</s>
<s>
Research	O
on	O
Prograph	B-Language
started	O
at	O
Acadia	O
University	O
in	O
1982	O
as	O
a	O
general	O
investigation	O
into	O
dataflow	B-Application
languages	I-Application
,	O
stimulated	O
by	O
a	O
seminar	O
on	O
functional	B-Language
languages	I-Language
conducted	O
by	O
Michael	O
Levin	O
.	O
</s>
<s>
Thus	O
Prograph	B-Language
-	O
Programming	O
in	O
Graphics	O
-	O
was	O
born	O
as	O
a	O
visual	B-Language
dataflow	B-Application
language	I-Application
.	O
</s>
<s>
From	O
1983	O
to	O
1985	O
,	O
research	O
prototypes	O
were	O
built	O
on	O
a	O
Three	B-Device
Rivers	I-Device
PERQ	I-Device
graphics	O
workstation	B-Device
(	O
in	O
Pascal	B-Application
,	O
with	O
the	O
data	O
visualized	O
as	O
fireballs	O
moving	O
down	O
datalinks	O
)	O
,	O
and	O
a	O
VAX	B-Device
with	O
a	O
Tektronix	O
terminal	O
,	O
and	O
an	O
experimental	O
compiler	O
was	O
programmed	O
in	O
an	O
IBM	O
PC	B-Device
.	O
</s>
<s>
This	O
work	O
was	O
continued	O
at	O
Technical	O
University	O
of	O
Nova	O
Scotia	O
by	O
Pietrzykowski	O
and	O
Dr.	O
Philip	O
Cox	O
,	O
including	O
a	O
version	O
done	O
in	O
Prolog	B-Language
.	O
</s>
<s>
In	O
1985	O
,	O
work	O
began	O
on	O
a	O
commercialisable	O
prototype	O
on	O
the	O
Macintosh	B-Device
,	O
the	O
only	O
widely	O
available	O
,	O
low-priced	O
computer	O
with	O
high-level	O
graphics	O
support	O
available	O
at	O
the	O
time	O
.	O
</s>
<s>
In	O
1987	O
Mark	O
Szpakowski	O
suggested	O
the	O
merger	O
of	O
object-orientation	O
with	O
visual	B-Language
dataflow	B-Application
,	O
creating	O
an	O
"	O
objectflow	O
"	O
system	O
.	O
</s>
<s>
TGS	O
changed	O
its	O
name	O
to	O
Prograph	B-Language
International	O
(	O
PI	O
)	O
in	O
1990	O
.	O
</s>
<s>
Although	O
sales	O
were	O
slow	O
,	O
development	O
of	O
a	O
new	O
version	O
,	O
Prograph	B-Language
CPX	I-Language
(	O
Cross-Platform	B-Operating_System
eXtensions	O
)	O
was	O
undertaken	O
in	O
1992	O
,	O
that	O
was	O
intended	O
to	O
build	O
fully	O
cross-platform	B-Operating_System
applications	O
.	O
</s>
<s>
Shortly	O
afterwards	O
,	O
development	O
of	O
a	O
Windows	B-Application
version	O
of	O
Prograph	B-Language
CPX	I-Language
was	O
begun	O
.	O
</s>
<s>
Although	O
it	O
was	O
never	O
formally	O
released	O
,	O
versions	O
of	O
Windows	B-Application
Prograph	B-Language
were	O
regularly	O
made	O
available	O
to	O
Prograph	B-Language
CPX	I-Language
customers	O
,	O
some	O
of	O
whom	O
ported	O
existing	O
applications	O
written	O
in	O
Macintosh	B-Device
Prograph	B-Language
,	O
with	O
varying	O
degrees	O
of	O
success	O
.	O
</s>
<s>
The	O
Pictorius	O
name	O
and	O
rights	O
to	O
the	O
Prograph	B-Language
source	O
code	O
were	O
retained	O
by	O
McLean	O
Watson	O
Capital	O
,	O
a	O
Toronto-based	O
investments	O
firm	O
which	O
had	O
heavily	O
funded	O
Pictorius	O
.	O
</s>
<s>
The	O
Windows	B-Application
version	O
of	O
CPX	O
was	O
later	O
released	O
for	O
free	O
use	O
,	O
and	O
was	O
available	O
for	O
some	O
time	O
for	O
download	O
from	O
the	O
remnants	O
of	O
the	O
Pictorius	O
website	O
(	O
link	O
below	O
)	O
.	O
</s>
<s>
A	O
group	O
of	O
Prograph	B-Language
users	O
(	O
"	O
Prographers	O
"	O
)	O
calling	O
themselves	O
""	O
(	O
OPI	O
)	O
formed	O
in	O
the	O
late	O
1990s	O
with	O
the	O
goal	O
of	O
keeping	O
Prograph	B-Language
viable	O
in	O
the	O
face	O
of	O
OS	O
advances	O
by	O
Apple	O
and	O
Microsoft	O
.	O
</s>
<s>
For	O
a	O
time	O
,	O
the	O
group	O
also	O
sought	O
to	O
create	O
a	O
new	O
open-source	O
visual	B-Language
programming	I-Language
language	I-Language
to	O
serve	O
as	O
Prograph	B-Language
's	O
successor	O
,	O
but	O
with	O
the	O
advent	O
of	O
Andescotia	O
's	O
Marten	O
visual	B-Language
programming	I-Language
environment	O
,	O
participation	O
in	O
the	O
group	O
essentially	O
ceased	O
.	O
</s>
<s>
The	O
Prograph	B-Language
language	O
is	O
supported	O
by	O
the	O
Marten	O
IDE	O
from	O
Andescotia	O
Software	O
.	O
</s>
<s>
Working	O
on	O
that	O
basis	O
,	O
a	O
number	O
of	O
new	O
programming	O
systems	O
evolved	O
,	O
including	O
object-oriented	B-Language
programming	I-Language
and	O
dataflow	B-Application
programming	I-Application
.	O
</s>
<s>
Prograph	B-Language
took	O
these	O
concept	O
further	O
,	O
introducing	O
a	O
combination	O
of	O
object-oriented	B-Language
methodologies	O
and	O
a	O
completely	O
visual	B-Language
environment	O
for	O
programming	O
.	O
</s>
<s>
In	O
Prograph	B-Language
a	O
method	O
is	O
represented	O
by	O
a	O
series	O
of	O
icons	O
,	O
each	O
icon	O
containing	O
an	O
instructions	O
(	O
or	O
group	O
of	O
them	O
)	O
.	O
</s>
<s>
Within	O
each	O
method	O
the	O
flow	B-Application
of	I-Application
data	I-Application
is	O
represented	O
by	O
lines	O
in	O
a	O
directed	O
graph	O
.	O
</s>
<s>
Data	B-Application
flows	I-Application
in	O
the	O
top	O
of	O
the	O
diagram	O
,	O
passes	O
through	O
various	O
instructions	O
,	O
and	O
eventually	O
flows	O
back	O
out	O
the	O
bottom	O
(	O
if	O
there	O
is	O
any	O
output	O
)	O
.	O
</s>
<s>
Several	O
features	O
of	O
the	O
Prograph	B-Language
system	O
are	O
evident	O
in	O
this	O
picture	O
of	O
a	O
database	O
sorting	O
operation	O
.	O
</s>
<s>
In	O
a	O
dataflow	B-Application
language	I-Application
the	O
operations	O
can	O
take	O
place	O
as	O
soon	O
as	O
they	O
have	O
valid	O
inputs	O
for	O
all	O
of	O
their	O
connections	O
.	O
</s>
<s>
Dataflow	B-Application
languages	I-Application
tend	O
to	O
be	O
inherently	O
concurrent	O
,	O
meaning	O
they	O
are	O
capable	O
of	O
running	O
on	O
multiprocessor	B-Operating_System
systems	O
"	O
naturally	O
"	O
,	O
one	O
of	O
the	O
reasons	O
that	O
it	O
garnered	O
so	O
much	O
interest	O
in	O
the	O
1980s	O
.	O
</s>
<s>
Another	O
annotation	O
,	O
"	O
injection	O
"	O
,	O
allows	O
the	O
method	O
itself	O
to	O
be	O
provided	O
as	O
an	O
input	O
,	O
making	O
Prograph	B-Language
a	O
dynamic	B-Language
language	I-Language
to	O
some	O
degree	O
.	O
</s>
<s>
The	O
integrated	O
Prograph	B-Language
development	O
and	O
execution	O
environment	O
also	O
allowed	O
for	O
visual	B-Language
debugging	O
.	O
</s>
<s>
Each	O
operation	O
in	O
a	O
data	B-Application
flow	I-Application
diagram	I-Application
was	O
visually	O
highlighted	O
as	O
it	O
executed	O
.	O
</s>
<s>
Visual	B-Language
display	O
of	O
the	O
execution	O
stack	O
allowed	O
for	O
both	O
roll-back	O
and	O
roll-forward	O
execution	O
.	O
</s>
<s>
For	O
many	O
users	O
the	O
visual	B-Language
execution	O
aspects	O
of	O
the	O
language	O
were	O
as	O
important	O
as	O
its	O
edit-time	O
graphical	O
facilities	O
.	O
</s>
<s>
Several	O
problems	O
with	O
the	O
Prograph	B-Language
system	O
are	O
also	O
evident	O
in	O
this	O
method	O
implementation	O
.	O
</s>
<s>
Prograph	B-Language
code	O
could	O
be	O
commented	O
using	O
labels	O
.	O
</s>
<s>
In	O
the	O
Prograph	B-Language
Database	O
Operation	O
example	O
above	O
,	O
two	O
of	O
the	O
paths	O
cross	O
because	O
one	O
of	O
the	O
wires	O
from	O
the	O
input	O
bar	O
must	O
flow	O
to	O
a	O
certain	O
input	O
on	O
the	O
update	O
operation	O
.	O
</s>
<s>
Another	O
problem	O
was	O
a	O
profusion	O
of	O
windows	B-Application
.	O
</s>
<s>
When	O
moving	O
around	O
the	O
Prograph	B-Language
workspace	O
,	O
the	O
IDE	O
generally	O
required	O
a	O
new	O
window	O
to	O
be	O
opened	O
to	O
see	O
the	O
contents	O
of	O
methods	O
.	O
</s>
