<s>
Pascal	B-Application
is	O
an	O
imperative	B-Application
and	O
procedural	B-Application
programming	I-Application
language	I-Application
,	O
designed	O
by	O
Niklaus	O
Wirth	O
as	O
a	O
small	O
,	O
efficient	O
language	O
intended	O
to	O
encourage	O
good	O
programming	O
practices	O
using	O
structured	B-Language
programming	I-Language
and	O
data	B-General_Concept
structuring	I-General_Concept
.	O
</s>
<s>
It	O
is	O
named	O
in	O
honour	O
of	O
the	O
French	O
mathematician	O
,	O
philosopher	O
and	O
physicist	O
Blaise	O
Pascal	B-Application
.	O
</s>
<s>
Pascal	B-Application
was	O
developed	O
on	O
the	O
pattern	O
of	O
the	O
ALGOL	B-Language
60	I-Language
language	O
.	O
</s>
<s>
Wirth	O
was	O
involved	O
in	O
the	O
process	O
to	O
improve	O
the	O
language	O
as	O
part	O
of	O
the	O
ALGOL	B-Language
X	I-Language
efforts	O
and	O
proposed	O
a	O
version	O
named	O
ALGOL	B-Language
W	I-Language
.	O
This	O
was	O
not	O
accepted	O
,	O
and	O
the	O
ALGOL	B-Language
X	I-Language
process	O
bogged	O
down	O
.	O
</s>
<s>
In	O
1968	O
,	O
Wirth	O
decided	O
to	O
abandon	O
the	O
ALGOL	B-Language
X	I-Language
process	O
and	O
further	O
improve	O
ALGOL	B-Language
W	I-Language
,	O
releasing	O
this	O
as	O
Pascal	B-Application
in	O
1970	O
.	O
</s>
<s>
On	O
top	O
of	O
ALGOL	B-Language
's	O
scalars	O
and	O
arrays	O
,	O
Pascal	B-Application
enables	O
defining	O
complex	O
datatypes	O
and	O
building	O
dynamic	O
and	O
recursive	O
data	B-General_Concept
structures	I-General_Concept
such	O
as	O
lists	O
,	O
trees	O
and	O
graphs	O
.	O
</s>
<s>
Pascal	B-Application
has	O
strong	O
typing	O
on	O
all	O
objects	O
,	O
which	O
means	O
that	O
one	O
type	O
of	O
data	O
cannot	O
be	O
converted	O
to	O
or	O
interpreted	O
as	O
another	O
without	O
explicit	O
conversions	O
.	O
</s>
<s>
Unlike	O
C	B-Language
(	O
and	O
most	O
languages	O
in	O
the	O
C-family	B-Language
)	O
,	O
Pascal	B-Application
allows	O
nested	O
procedure	O
definitions	O
to	O
any	O
level	O
of	O
depth	O
,	O
and	O
also	O
allows	O
most	O
kinds	O
of	O
definitions	O
and	O
declarations	O
inside	O
subroutines	O
(	O
procedures	O
and	O
functions	O
)	O
.	O
</s>
<s>
This	O
is	O
similar	O
to	O
the	O
block	O
structure	O
of	O
ALGOL	B-Language
60	I-Language
,	O
but	O
restricted	O
from	O
arbitrary	O
block	O
statements	O
to	O
just	O
procedures	O
and	O
functions	O
.	O
</s>
<s>
Pascal	B-Application
became	O
very	O
successful	O
in	O
the	O
1970s	O
,	O
notably	O
on	O
the	O
burgeoning	O
minicomputer	B-Architecture
market	O
.	O
</s>
<s>
Compilers	B-Language
were	O
also	O
available	O
for	O
many	O
microcomputers	B-Architecture
as	O
the	O
field	O
emerged	O
in	O
the	O
late	O
1970s	O
.	O
</s>
<s>
It	O
was	O
displaced	O
by	O
the	O
C	B-Language
programming	I-Language
language	I-Language
during	O
the	O
late	O
1980s	O
and	O
early	O
1990s	O
as	O
UNIX-based	O
systems	O
became	O
popular	O
,	O
and	O
especially	O
with	O
the	O
release	O
of	O
C++	B-Language
.	O
</s>
<s>
A	O
derivative	O
named	O
Object	B-Language
Pascal	I-Language
designed	O
for	O
object-oriented	B-Language
programming	I-Language
was	O
developed	O
in	O
1985	O
.	O
</s>
<s>
This	O
was	O
used	O
by	O
Apple	O
Computer	O
(	O
for	O
the	O
Lisa	B-Device
and	O
Macintosh	B-Device
machines	O
)	O
and	O
Borland	O
in	O
the	O
late	O
1980s	O
and	O
later	O
developed	O
into	O
Delphi	B-Language
on	O
the	O
Microsoft	B-Application
Windows	I-Application
platform	O
.	O
</s>
<s>
Extensions	O
to	O
the	O
Pascal	B-Application
concepts	O
led	O
to	O
the	O
languages	O
Modula-2	B-Language
and	O
Oberon	B-Language
.	O
</s>
<s>
Much	O
of	O
the	O
history	O
of	O
computer	B-Language
language	I-Language
design	O
during	O
the	O
1960s	O
can	O
be	O
traced	O
to	O
the	O
ALGOL	B-Language
60	I-Language
language	O
.	O
</s>
<s>
ALGOL	B-Language
was	O
developed	O
during	O
the	O
1950s	O
with	O
the	O
explicit	O
goal	O
of	O
being	O
able	O
to	O
clearly	O
describe	O
algorithms	O
.	O
</s>
<s>
It	O
included	O
a	O
number	O
of	O
features	O
for	O
structured	B-Language
programming	I-Language
that	O
remain	O
common	O
in	O
languages	O
to	O
this	O
day	O
.	O
</s>
<s>
Shortly	O
after	O
its	O
introduction	O
,	O
in	O
1962	O
Wirth	O
began	O
working	O
on	O
his	O
dissertation	O
with	O
Helmut	O
Weber	O
on	O
the	O
Euler	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
Euler	B-Language
was	O
based	O
on	O
ALGOL	B-Language
's	O
syntax	O
and	O
many	O
concepts	O
but	O
was	O
not	O
a	O
derivative	O
.	O
</s>
<s>
Its	O
primary	O
goal	O
was	O
to	O
add	O
dynamic	B-Data_Structure
lists	I-Data_Structure
and	O
types	O
,	O
allowing	O
it	O
to	O
be	O
used	O
in	O
roles	O
similar	O
to	O
Lisp	B-Language
.	O
</s>
<s>
By	O
this	O
time	O
,	O
a	O
number	O
of	O
problems	O
in	O
ALGOL	B-Language
had	O
been	O
identified	O
,	O
notably	O
the	O
lack	O
of	O
a	O
standardized	O
string	O
system	O
.	O
</s>
<s>
The	O
group	O
tasked	O
with	O
maintaining	O
the	O
language	O
had	O
begun	O
the	O
ALGOL	B-Language
X	I-Language
process	O
to	O
identify	O
improvements	O
,	O
calling	O
for	O
submissions	O
.	O
</s>
<s>
These	O
were	O
considered	O
too	O
minor	O
to	O
be	O
worth	O
using	O
as	O
the	O
new	O
standard	O
ALGOL	B-Language
,	O
so	O
Wirth	O
wrote	O
a	O
compiler	B-Language
for	O
the	O
language	O
,	O
which	O
became	O
named	O
ALGOL	B-Language
W	I-Language
.	O
</s>
<s>
The	O
ALGOL	B-Language
X	I-Language
efforts	O
would	O
go	B-Application
on	O
to	O
choose	O
a	O
much	O
more	O
complex	O
language	O
,	O
ALGOL	B-Language
68	I-Language
.	O
</s>
<s>
The	O
complexity	O
of	O
this	O
language	O
led	O
to	O
considerable	O
difficulty	O
producing	O
high-performance	O
compilers	B-Language
,	O
and	O
it	O
was	O
not	O
widely	O
used	O
in	O
the	O
industry	O
.	O
</s>
<s>
Pascal	B-Application
was	O
influenced	O
by	O
the	O
ALGOL	B-Language
W	I-Language
efforts	O
,	O
with	O
the	O
explicit	O
goals	O
of	O
teaching	O
programming	O
in	O
a	O
structured	B-Language
fashion	I-Language
and	O
for	O
the	O
development	O
of	O
system	B-Application
software	I-Application
.	O
</s>
<s>
A	O
generation	O
of	O
students	O
used	O
Pascal	B-Application
as	O
an	O
introductory	O
language	O
in	O
undergraduate	O
courses	O
.	O
</s>
<s>
One	O
of	O
the	O
early	O
successes	O
for	O
the	O
language	O
was	O
the	O
introduction	O
of	O
UCSD	B-Language
Pascal	I-Language
,	O
a	O
version	O
that	O
ran	O
on	O
a	O
custom	O
operating	B-General_Concept
system	I-General_Concept
that	O
could	O
be	O
ported	O
to	O
different	O
platforms	O
.	O
</s>
<s>
A	O
key	O
platform	O
was	O
the	O
Apple	B-Device
II	I-Device
,	O
where	O
it	O
saw	O
widespread	O
use	O
as	O
Apple	B-Operating_System
Pascal	I-Operating_System
.	O
</s>
<s>
This	O
led	O
to	O
Pascal	B-Application
becoming	O
the	O
primary	O
high-level	O
language	O
used	O
for	O
development	O
in	O
the	O
Apple	B-Device
Lisa	I-Device
,	O
and	O
later	O
,	O
the	O
Macintosh	B-Device
.	O
</s>
<s>
Parts	O
of	O
the	O
original	O
Macintosh	B-Application
operating	I-Application
system	I-Application
were	O
hand-translated	O
into	O
Motorola	B-Device
68000	I-Device
assembly	B-Language
language	I-Language
from	O
the	O
Pascal	B-Application
source	O
code	O
.	O
</s>
<s>
The	O
typesetting	O
system	O
TeX	B-Application
by	O
Donald	O
E	O
.	O
Knuth	O
was	O
written	O
in	O
WEB	O
,	O
the	O
original	O
literate	B-Application
programming	I-Application
system	O
,	O
based	O
on	O
DEC	B-Device
PDP-10	I-Device
Pascal	B-Application
.	O
</s>
<s>
Successful	O
commercial	O
applications	O
like	O
Adobe	B-Operating_System
Photoshop	I-Operating_System
were	O
written	O
in	O
Macintosh	B-Operating_System
Programmer	I-Operating_System
's	I-Operating_System
Workshop	I-Operating_System
Pascal	B-Application
,	O
while	O
applications	O
like	O
Total	B-Language
Commander	I-Language
,	O
Skype	B-Application
and	O
Macromedia	O
Captivate	O
were	O
written	O
in	O
Delphi	B-Language
(	O
Object	B-Language
Pascal	I-Language
)	O
.	O
</s>
<s>
Apollo	O
Computer	O
used	O
Pascal	B-Application
as	O
the	O
systems	O
programming	O
language	O
for	O
its	O
operating	B-General_Concept
systems	I-General_Concept
beginning	O
in	O
1980	O
.	O
</s>
<s>
Variants	O
of	O
Pascal	B-Application
have	O
also	O
been	O
used	O
for	O
everything	O
from	O
research	O
projects	O
to	O
PC	O
games	O
and	O
embedded	B-Architecture
systems	I-Architecture
.	O
</s>
<s>
Newer	O
Pascal	B-Application
compilers	B-Language
exist	O
which	O
are	O
widely	O
used	O
.	O
</s>
<s>
During	O
work	O
on	O
the	O
Lisa	B-Device
,	O
Larry	O
Tesler	O
began	O
corresponding	O
with	O
Wirth	O
on	O
the	O
idea	O
of	O
adding	O
object-oriented	B-Language
extensions	O
to	O
the	O
language	O
,	O
to	O
make	O
Pascal	B-Application
a	O
Multi-paradigm	O
programming	O
language	O
.	O
</s>
<s>
This	O
led	O
initially	O
to	O
Clascal	B-Language
,	O
introduced	O
in	O
1983	O
.	O
</s>
<s>
As	O
the	O
Lisa	B-Device
program	O
faded	O
and	O
was	O
replaced	O
by	O
the	O
Macintosh	B-Device
,	O
a	O
further	O
version	O
was	O
created	O
and	O
named	O
Object	B-Language
Pascal	I-Language
.	O
</s>
<s>
This	O
was	O
introduced	O
on	O
the	O
Mac	O
in	O
1985	O
as	O
part	O
of	O
the	O
MacApp	B-Operating_System
application	B-Application
framework	I-Application
,	O
and	O
became	O
Apple	O
's	O
main	O
development	O
language	O
into	O
the	O
early	O
1990s	O
.	O
</s>
<s>
The	O
Object	B-Language
Pascal	I-Language
extensions	O
were	O
added	O
to	O
Turbo	B-Application
Pascal	I-Application
with	O
the	O
release	O
of	O
version	O
5.5	O
in	O
1989	O
.	O
</s>
<s>
Over	O
the	O
years	O
,	O
Object	B-Language
Pascal	I-Language
became	O
the	O
basis	O
of	O
the	O
Delphi	B-Language
system	O
for	O
Microsoft	B-Application
Windows	I-Application
,	O
which	O
is	O
still	O
used	O
for	O
developing	O
Windows	B-Application
applications	I-Application
,	O
and	O
can	O
cross-compile	B-Application
code	O
to	O
other	O
systems	O
.	O
</s>
<s>
Free	B-Operating_System
Pascal	I-Operating_System
is	O
an	O
open	B-Application
source	I-Application
,	O
cross-platform	B-Operating_System
alternative	O
with	O
its	O
own	O
graphical	O
IDE	B-Application
called	O
Lazarus	B-Language
.	O
</s>
<s>
The	O
first	O
Pascal	B-Application
compiler	B-Language
was	O
designed	O
in	O
Zürich	O
for	O
the	O
CDC	B-Device
6000	I-Device
series	I-Device
mainframe	B-Architecture
computer	I-Architecture
family	O
.	O
</s>
<s>
Niklaus	O
Wirth	O
reports	O
that	O
a	O
first	O
attempt	O
to	O
implement	O
it	O
in	O
FORTRAN	B-Application
66	I-Application
in	O
1969	O
was	O
unsuccessful	O
due	O
to	O
FORTRAN	B-Application
66	I-Application
's	O
inadequacy	O
to	O
express	O
complex	O
data	B-General_Concept
structures	I-General_Concept
.	O
</s>
<s>
The	O
second	O
attempt	O
was	O
implemented	O
in	O
a	O
C-like	B-Language
language	O
(	O
Scallop	O
by	O
Max	O
Engeli	O
)	O
and	O
then	O
translated	O
by	O
hand	O
(	O
by	O
R	O
.	O
Schild	O
)	O
to	O
Pascal	B-Application
itself	O
for	O
boot-strapping	O
.	O
</s>
<s>
Many	O
Pascal	B-Application
compilers	B-Language
since	O
have	O
been	O
similarly	O
self-hosting	O
,	O
that	O
is	O
,	O
the	O
compiler	B-Language
is	O
itself	O
written	O
in	O
Pascal	B-Application
,	O
and	O
the	O
compiler	B-Language
is	O
usually	O
capable	O
of	O
recompiling	O
itself	O
when	O
new	O
features	O
are	O
added	O
to	O
the	O
language	O
,	O
or	O
when	O
the	O
compiler	B-Language
is	O
to	O
be	O
ported	O
to	O
a	O
new	O
environment	O
.	O
</s>
<s>
The	O
GNU	B-Language
Pascal	I-Language
compiler	B-Language
is	O
one	O
notable	O
exception	O
,	O
being	O
written	O
in	O
C	B-Language
.	O
</s>
<s>
The	O
first	O
successful	O
port	O
of	O
the	O
CDC	O
Pascal	B-Application
compiler	B-Language
to	O
another	O
mainframe	B-Architecture
was	O
completed	O
by	O
Welsh	O
and	O
Quinn	O
at	O
the	O
Queen	O
's	O
University	O
of	O
Belfast	O
(	O
QUB	O
)	O
in	O
1972	O
.	O
</s>
<s>
The	O
target	O
was	O
the	O
International	O
Computers	O
Limited	O
(	O
ICL	O
)	O
1900	B-Device
series	I-Device
.	O
</s>
<s>
This	O
compiler	B-Language
,	O
in	O
turn	O
,	O
was	O
the	O
parent	O
of	O
the	O
Pascal	B-Application
compiler	B-Language
for	O
the	O
Information	O
Computer	O
Systems	O
(	O
ICS	O
)	O
Multum	B-Device
minicomputer	B-Architecture
.	O
</s>
<s>
The	O
Multum	B-Device
port	O
was	O
developed	O
–	O
with	O
a	O
view	O
to	O
using	O
Pascal	B-Application
as	O
a	O
systems	O
programming	O
language	O
–	O
by	O
Findlay	O
,	O
Cupples	O
,	O
Cavouras	O
and	O
Davis	O
,	O
working	O
at	O
the	O
Department	O
of	O
Computing	O
Science	O
in	O
Glasgow	O
University	O
.	O
</s>
<s>
It	O
is	O
thought	O
that	O
Multum	B-Device
Pascal	B-Application
,	O
which	O
was	O
completed	O
in	O
the	O
summer	O
of	O
1973	O
,	O
may	O
have	O
been	O
the	O
first	O
16-bit	O
implementation	O
.	O
</s>
<s>
A	O
completely	O
new	O
compiler	B-Language
was	O
completed	O
by	O
Welsh	O
et	O
al	O
.	O
</s>
<s>
This	O
implementation	O
was	O
ported	O
in	O
1980	O
to	O
the	O
ICL	B-Device
2900	I-Device
series	I-Device
by	O
a	O
team	O
based	O
at	O
Southampton	O
University	O
and	O
Glasgow	O
University	O
.	O
</s>
<s>
The	O
Standard	O
Pascal	B-Application
Model	O
Implementation	O
was	O
also	O
based	O
on	O
this	O
compiler	B-Language
,	O
having	O
been	O
adapted	O
,	O
by	O
Welsh	O
and	O
Hay	O
at	O
Manchester	O
University	O
in	O
1984	O
,	O
to	O
check	O
rigorously	O
for	O
conformity	O
to	O
the	O
BSI	O
6192/ISO	O
7185	O
Standard	O
and	O
to	O
generate	O
code	O
for	O
a	O
portable	O
abstract	O
machine	O
.	O
</s>
<s>
The	O
first	O
Pascal	B-Application
compiler	B-Language
written	O
in	O
North	O
America	O
was	O
constructed	O
at	O
the	O
University	O
of	O
Illinois	O
under	O
Donald	O
B	O
.	O
Gillies	O
for	O
the	O
PDP-11	B-Device
and	O
generated	O
native	O
machine	O
code	O
.	O
</s>
<s>
To	O
propagate	O
the	O
language	O
rapidly	O
,	O
a	O
compiler	B-Language
porting	O
kit	O
was	O
created	O
in	O
Zürich	O
that	O
included	O
a	O
compiler	B-Language
that	O
generated	O
so	O
called	O
p-code	B-Language
for	O
a	O
virtual	O
stack	B-Application
machine	O
,	O
i.e.	O
,	O
code	O
that	O
lends	O
itself	O
to	O
reasonably	O
efficient	O
interpretation	O
,	O
along	O
with	O
an	O
interpreter	B-Application
for	O
that	O
code	O
–	O
the	O
Pascal-P	O
system	O
.	O
</s>
<s>
The	O
P-system	B-Language
compilers	B-Language
were	O
named	O
Pascal-P1	O
,	O
Pascal-P2	B-Application
,	O
Pascal-P3	O
,	O
and	O
Pascal-P4	O
.	O
</s>
<s>
Pascal-P1	O
was	O
the	O
first	O
version	O
,	O
and	O
Pascal-P4	O
was	O
the	O
last	O
to	O
come	O
from	O
Zürich	O
.	O
</s>
<s>
The	O
version	O
termed	O
Pascal-P1	O
was	O
coined	O
after	O
the	O
fact	O
for	O
the	O
many	O
different	O
sources	O
for	O
Pascal-P	O
that	O
existed	O
.	O
</s>
<s>
The	O
compiler	B-Language
was	O
redesigned	O
to	O
enhance	O
portability	O
,	O
and	O
issued	O
as	O
Pascal-P2	B-Application
.	O
</s>
<s>
This	O
code	O
was	O
later	O
enhanced	O
to	O
become	O
Pascal-P3	O
,	O
with	O
an	O
intermediate	O
code	O
backward	B-General_Concept
compatible	I-General_Concept
with	O
Pascal-P2	B-Application
,	O
and	O
Pascal-P4	O
,	O
which	O
was	O
not	O
backward	B-General_Concept
compatible	I-General_Concept
.	O
</s>
<s>
The	O
Pascal-P4	O
compiler	B-Language
–	O
interpreter	B-Application
can	O
still	O
be	O
run	O
and	O
compiled	B-Language
on	O
systems	O
compatible	O
with	O
original	O
Pascal	B-Application
.	O
</s>
<s>
However	O
,	O
it	O
only	O
accepts	O
a	O
subset	O
of	O
the	O
Pascal	B-Application
language	I-Application
.	O
</s>
<s>
Pascal-P5	O
,	O
created	O
outside	O
the	O
Zürich	O
group	O
,	O
accepts	O
the	O
full	O
Pascal	B-Application
language	I-Application
and	O
includes	O
ISO	B-Application
7185	I-Application
compatibility	O
.	O
</s>
<s>
UCSD	B-Language
Pascal	I-Language
branched	O
off	O
Pascal-P2	B-Application
,	O
where	O
Kenneth	O
Bowles	O
used	O
it	O
to	O
create	O
the	O
interpretive	B-Application
UCSD	B-Language
p-System	I-Language
.	O
</s>
<s>
It	O
was	O
one	O
of	O
three	O
operating	B-General_Concept
systems	I-General_Concept
available	O
at	O
the	O
launch	O
of	O
the	O
original	O
IBM	B-Device
Personal	I-Device
Computer	I-Device
.	O
</s>
<s>
UCSD	B-Language
Pascal	I-Language
used	O
an	O
intermediate	O
code	O
based	O
on	O
byte	O
values	O
,	O
and	O
thus	O
was	O
one	O
of	O
the	O
earliest	O
bytecode	O
compilers	B-Language
.	O
</s>
<s>
Apple	B-Operating_System
Pascal	I-Operating_System
was	O
released	O
in	O
1979	O
for	O
the	O
Apple	B-Device
2	I-Device
and	O
Apple	O
3	O
computer	O
systems	O
.	O
</s>
<s>
It	O
was	O
an	O
implementation	O
of	O
,	O
or	O
largely	O
based	O
on	O
,	O
UCSD	B-Language
Pascal	I-Language
.	O
</s>
<s>
Pascal-P1	O
through	O
Pascal-P4	O
was	O
not	O
,	O
but	O
rather	O
based	O
on	O
the	O
CDC	O
6600	O
60-bit	O
word	O
length	O
.	O
</s>
<s>
A	O
compiler	B-Language
based	O
on	O
the	O
Pascal-P5	O
compiler	B-Language
,	O
which	O
created	O
native	O
binary	O
object	O
files	B-Operating_System
,	O
was	O
released	O
for	O
the	O
IBM	B-Device
System/370	I-Device
mainframe	B-Architecture
computer	I-Architecture
by	O
the	O
Australian	O
Atomic	O
Energy	O
Commission	O
;	O
it	O
was	O
named	O
the	O
AAEC	O
Pascal	B-Application
8000	O
Compiler	B-Language
after	O
the	O
abbreviation	O
of	O
the	O
name	O
of	O
the	O
commission	O
.	O
</s>
<s>
Apple	O
Computer	O
created	O
its	O
own	O
Lisa	B-Device
Pascal	B-Application
for	O
the	O
Lisa	B-Device
Workshop	O
in	O
1982	O
,	O
and	O
ported	O
the	O
compiler	B-Language
to	O
the	O
Apple	O
Macintosh	B-Device
and	O
MPW	B-Operating_System
in	O
1985	O
.	O
</s>
<s>
In	O
1985	O
Larry	O
Tesler	O
,	O
in	O
consultation	O
with	O
Niklaus	O
Wirth	O
,	O
defined	O
Object	B-Language
Pascal	I-Language
and	O
these	O
extensions	O
were	O
incorporated	O
in	O
both	O
the	O
Lisa	B-Device
Pascal	B-Application
and	O
Mac	O
Pascal	B-Application
compilers	B-Language
.	O
</s>
<s>
In	O
the	O
1980s	O
,	O
Anders	O
Hejlsberg	O
wrote	O
the	O
Blue	O
Label	O
Pascal	B-Application
compiler	B-Language
for	O
the	O
Nascom-2	B-Operating_System
.	O
</s>
<s>
A	O
reimplementation	O
of	O
this	O
compiler	B-Language
for	O
the	O
IBM	B-Device
PC	I-Device
was	O
marketed	O
under	O
the	O
names	O
Compas	O
Pascal	B-Application
and	O
PolyPascal	O
before	O
it	O
was	O
acquired	O
by	O
Borland	O
and	O
renamed	O
Turbo	B-Application
Pascal	I-Application
.	O
</s>
<s>
Turbo	B-Application
Pascal	I-Application
became	O
hugely	O
popular	O
,	O
thanks	O
to	O
an	O
aggressive	O
pricing	O
strategy	O
,	O
having	O
one	O
of	O
the	O
first	O
full-screen	O
IDEs	O
,	O
and	O
very	O
fast	O
turnaround	O
time	O
(	O
just	O
seconds	O
to	O
compile	B-Language
,	O
link	O
,	O
and	O
run	O
)	O
.	O
</s>
<s>
It	O
was	O
written	O
and	O
highly	O
optimized	O
entirely	O
in	O
assembly	B-Language
language	I-Language
,	O
making	O
it	O
smaller	O
and	O
faster	O
than	O
much	O
of	O
the	O
competition	O
.	O
</s>
<s>
In	O
1986	O
,	O
Anders	O
ported	O
Turbo	B-Application
Pascal	I-Application
to	O
the	O
Macintosh	B-Device
and	O
incorporated	O
Apple	O
's	O
Object	B-Language
Pascal	I-Language
extensions	O
into	O
Turbo	B-Application
Pascal	I-Application
.	O
</s>
<s>
These	O
extensions	O
were	O
then	O
added	O
back	O
into	O
the	O
PC	O
version	O
of	O
Turbo	B-Application
Pascal	I-Application
for	O
version	O
5.5	O
.	O
</s>
<s>
At	O
the	O
same	O
time	O
Microsoft	O
also	O
implemented	O
the	O
Object	B-Language
Pascal	I-Language
compiler	B-Language
.	O
</s>
<s>
Turbo	B-Application
Pascal	I-Application
5.5	O
had	O
a	O
large	O
influence	O
on	O
the	O
Pascal	B-Application
community	O
,	O
which	O
began	O
concentrating	O
mainly	O
on	O
the	O
IBM	B-Device
PC	I-Device
in	O
the	O
late	O
1980s	O
.	O
</s>
<s>
Many	O
PC	O
hobbyists	O
in	O
search	O
of	O
a	O
structured	B-Language
replacement	O
for	O
BASIC	O
used	O
this	O
product	O
.	O
</s>
<s>
Around	O
the	O
same	O
time	O
a	O
number	O
of	O
concepts	O
were	O
imported	O
from	O
C	B-Language
to	O
let	O
Pascal	B-Application
programmers	O
use	O
the	O
C-based	O
application	B-Application
programming	I-Application
interface	I-Application
(	O
API	B-Application
)	O
of	O
Microsoft	B-Application
Windows	I-Application
directly	O
.	O
</s>
<s>
These	O
extensions	O
included	O
null-terminated	O
strings	O
,	O
pointer	O
arithmetic	O
,	O
function	B-Language
pointers	I-Language
,	O
an	O
address-of	O
operator	O
,	O
and	O
unsafe	O
typecasts	O
.	O
</s>
<s>
Turbo	B-Application
Pascal	I-Application
and	O
other	O
derivatives	O
with	O
unit	O
or	O
module	B-Architecture
structures	O
are	O
modular	B-Architecture
programming	I-Architecture
languages	O
.	O
</s>
<s>
However	O
,	O
it	O
does	O
not	O
provide	O
a	O
nested	O
module	B-Architecture
concept	O
or	O
qualified	O
import	O
and	O
export	O
of	O
specific	O
symbols	O
.	O
</s>
<s>
Super	B-Language
Pascal	I-Language
is	O
a	O
variant	O
that	O
added	O
non-numeric	O
labels	O
,	O
a	O
return	O
statement	O
and	O
expressions	O
as	O
names	O
of	O
types	O
.	O
</s>
<s>
TMT	O
Pascal	B-Application
was	O
the	O
first	O
Borland-compatible	O
compiler	B-Language
for	O
32-bit	O
DOS	B-Device
protected	B-Application
mode	I-Application
,	O
OS/2	B-Application
,	O
and	O
Win32	B-Library
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
The	O
TMT	O
Pascal	B-Application
language	I-Application
was	O
the	O
first	O
one	O
to	O
allow	O
function	O
and	O
operator	O
overloading	O
.	O
</s>
<s>
The	O
universities	O
of	O
Wisconsin-Madison	O
,	O
Zürich	O
,	O
Karlsruhe	B-Algorithm
,	O
and	O
Wuppertal	O
developed	O
the	O
Pascal-SC	O
and	O
Pascal-XSC	O
(	O
Extensions	O
for	O
Scientific	O
Computation	O
)	O
compilers	B-Language
,	O
aimed	O
at	O
programming	O
numerical	O
computations	O
.	O
</s>
<s>
Development	O
for	O
Pascal-SC	O
started	O
in	O
1978	O
supporting	O
ISO	B-Application
7185	I-Application
Pascal	B-Application
level	O
0	O
,	O
but	O
level	O
2	O
support	O
was	O
added	O
at	O
a	O
later	O
stage	O
.	O
</s>
<s>
Pascal-SC	O
originally	O
targeted	O
the	O
Z80	B-General_Concept
processor	O
,	O
but	O
was	O
later	O
rewritten	O
for	O
DOS	B-Device
(	O
x86	B-Operating_System
)	O
and	O
68000	B-Device
.	O
</s>
<s>
Pascal-XSC	O
has	O
at	O
various	O
times	O
been	O
ported	O
to	O
Unix	B-Application
(	O
Linux	B-Application
,	O
SunOS	B-Operating_System
,	O
HP-UX	B-Application
,	O
AIX	B-Application
)	O
and	O
Microsoft/IBM	O
(	O
DOS	B-Device
with	O
EMX	B-Device
,	O
OS/2	B-Application
,	O
Windows	B-Application
)	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
It	O
operates	O
by	O
generating	O
intermediate	O
C	B-Language
source	O
code	O
which	O
is	O
then	O
compiled	B-Language
to	O
a	O
native	O
executable	O
.	O
</s>
<s>
Some	O
of	O
the	O
Pascal-SC	O
language	O
extensions	O
have	O
been	O
adopted	O
by	O
GNU	B-Language
Pascal	I-Language
.	O
</s>
<s>
Pascal	B-Application
Sol	O
was	O
designed	O
around	O
1983	O
by	O
a	O
French	O
team	O
to	O
implement	O
a	O
Unix-like	B-Operating_System
system	I-Operating_System
named	O
Sol	O
.	O
</s>
<s>
It	O
was	O
standard	O
Pascal	B-Application
level-1	O
(	O
with	O
parameterized	O
array	O
bounds	O
)	O
but	O
the	O
definition	O
allowed	O
alternative	O
keywords	O
and	O
predefined	O
identifiers	O
in	O
French	O
and	O
the	O
language	O
included	O
a	O
few	O
extensions	O
to	O
ease	O
system	O
programming	O
(	O
e.g.	O
</s>
<s>
an	O
equivalent	O
to	O
lseek	B-Application
)	O
.	O
</s>
<s>
The	O
Sol	O
team	O
later	O
on	O
moved	O
to	O
the	O
ChorusOS	B-Operating_System
project	O
to	O
design	O
a	O
distributed	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
IP	B-Language
Pascal	I-Language
was	O
an	O
implementation	O
of	O
the	O
Pascal	B-Application
programming	I-Application
language	I-Application
using	O
Micropolis	O
DOS	B-Device
,	O
but	O
was	O
moved	O
rapidly	O
to	O
CP/M	B-Application
-80	I-Application
running	O
on	O
the	O
Z80	B-General_Concept
.	O
</s>
<s>
It	O
was	O
moved	O
to	O
the	O
80386	B-General_Concept
machine	O
types	O
in	O
1994	O
,	O
and	O
exists	O
today	O
as	O
Windows/XP	O
and	O
Linux	B-Application
implementations	O
.	O
</s>
<s>
In	O
2008	O
,	O
the	O
system	O
was	O
brought	O
up	O
to	O
a	O
new	O
level	O
and	O
the	O
resulting	O
language	O
termed	O
"	O
Pascaline	O
"	O
(	O
after	O
Pascal	B-Application
's	O
calculator	O
)	O
.	O
</s>
<s>
It	O
includes	O
objects	O
,	O
namespace	O
controls	O
,	O
dynamic	B-Data_Structure
arrays	I-Data_Structure
,	O
and	O
many	O
other	O
extensions	O
,	O
and	O
generally	O
features	O
the	O
same	O
functionality	O
and	O
type	O
protection	O
as	O
C#	B-Application
.	O
</s>
<s>
It	O
is	O
the	O
only	O
such	O
implementation	O
that	O
is	O
also	O
compatible	O
with	O
the	O
original	O
Pascal	B-Application
implementation	O
,	O
which	O
is	O
standardized	O
as	O
ISO	B-Application
7185	I-Application
.	O
</s>
<s>
Pascal	B-Application
,	O
in	O
its	O
original	O
form	O
,	O
is	O
a	O
purely	O
procedural	B-Application
language	I-Application
and	O
includes	O
the	O
traditional	O
array	O
of	O
ALGOL-like	B-Language
control	O
structures	O
with	O
reserved	O
words	O
such	O
as	O
if	O
,	O
then	O
,	O
else	O
,	O
while	O
,	O
for	O
,	O
and	O
case	O
,	O
ranging	O
on	O
a	O
single	O
statement	O
or	O
a	O
begin-end	O
statements	O
block	O
.	O
</s>
<s>
Pascal	B-Application
also	O
has	O
data	B-General_Concept
structuring	I-General_Concept
constructs	O
not	O
included	O
in	O
the	O
original	O
ALGOL	B-Language
60	I-Language
types	O
,	O
like	O
records	O
,	O
variants	O
,	O
pointers	O
,	O
enumerations	B-Language
,	O
and	O
sets	O
and	O
procedure	B-Language
pointers	I-Language
.	O
</s>
<s>
Such	O
constructs	O
were	O
in	O
part	O
inherited	O
or	O
inspired	O
from	O
Simula	B-Language
67	I-Language
,	O
ALGOL	B-Language
68	I-Language
,	O
Niklaus	O
Wirth	O
's	O
own	O
ALGOL	B-Language
W	I-Language
and	O
suggestions	O
by	O
C	B-Language
.	O
A	O
.	O
R	O
.	O
Hoare	O
.	O
</s>
<s>
Pascal	B-Application
programs	O
start	O
with	O
the	O
program	O
keyword	O
with	O
a	O
list	O
of	O
external	O
file	B-Application
descriptors	I-Application
as	O
parameters	O
(	O
not	O
required	O
in	O
Turbo	B-Application
Pascal	I-Application
etc	O
.	O
</s>
<s>
Letter	O
case	O
is	O
ignored	O
in	O
Pascal	B-Application
source	O
.	O
</s>
<s>
A	O
Type	O
Declaration	O
in	O
Pascal	B-Application
is	O
used	O
to	O
define	O
a	O
range	O
of	O
values	O
which	O
a	O
variable	O
of	O
that	O
type	O
is	O
capable	O
of	O
storing	O
.	O
</s>
<s>
Data	O
type	O
Type	O
of	O
values	O
which	O
the	O
variable	O
is	O
capable	O
of	O
storing	O
integer	O
integer	O
(	O
whole	O
)	O
numbers	O
real	B-Algorithm
floating-point	B-Algorithm
numbers	I-Algorithm
boolean	O
the	O
values	O
True	O
or	O
False	O
char	O
a	O
single	O
character	O
from	O
an	O
ordered	O
character	O
set	O
set	O
equivalent	O
to	O
an	O
array	O
of	O
boolean	O
values	O
array	O
a	O
countable	O
group	O
of	O
any	O
of	O
the	O
preceding	O
data	O
types	O
or	O
records	O
record	O
A	O
collection	O
of	O
any	O
of	O
the	O
preceding	O
data	O
types	O
string	O
a	O
sequence	O
or	O
"	O
string	O
"	O
of	O
characters	O
is	O
declared	O
as	O
a	O
"	O
packed	O
array	O
of	O
char	O
"	O
with	O
a	O
starting	O
index	O
of	O
1	O
.	O
</s>
<s>
For	O
conversion	O
of	O
real	B-Algorithm
to	O
integer	O
,	O
the	O
following	O
functions	O
are	O
available	O
:	O
round	O
(	O
which	O
rounds	O
to	O
integer	O
using	O
banker	O
's	O
rounding	O
)	O
and	O
trunc	O
(	O
rounds	O
towards	O
zero	O
)	O
.	O
</s>
<s>
Pascal	B-Application
does	O
not	O
contain	O
language	O
elements	O
that	O
allow	O
the	O
basic	O
storage	O
types	O
to	O
be	O
defined	O
more	O
granularly	O
.	O
</s>
<s>
This	O
capability	O
was	O
included	O
in	O
a	O
number	O
of	O
Pascal	B-Application
extensions	O
and	O
follow-on	O
languages	O
,	O
while	O
others	O
,	O
like	O
Modula-2	B-Language
,	O
expanded	O
the	O
built-in	O
set	O
to	O
cover	O
most	O
machine	O
data	O
types	O
like	O
16-bit	O
integers	O
.	O
</s>
<s>
The	O
keyword	O
tells	O
the	O
compiler	B-Language
to	O
use	O
the	O
most	O
efficient	O
method	O
of	O
storage	O
for	O
the	O
structured	B-Language
data	O
types	O
:	O
sets	O
,	O
arrays	O
and	O
records	O
,	O
rather	O
than	O
using	O
one	O
word	O
for	O
each	O
element	O
.	O
</s>
<s>
Subranges	O
of	O
any	O
ordinal	B-General_Concept
data	I-General_Concept
type	I-General_Concept
(	O
any	O
simple	O
type	O
except	O
real	B-Algorithm
)	O
can	O
also	O
be	O
made	O
:	O
</s>
<s>
In	O
contrast	O
with	O
other	O
programming	O
languages	O
from	O
its	O
time	O
,	O
Pascal	B-Application
supports	O
a	O
set	O
type	O
:	O
</s>
<s>
For	O
example	O
,	O
for	O
many	O
Pascal	B-Application
compilers	B-Language
:	O
</s>
<s>
For	O
these	O
examples	O
,	O
which	O
involve	O
sets	O
over	O
small	O
domains	O
,	O
the	O
improved	O
performance	O
is	O
usually	O
achieved	O
by	O
the	O
compiler	B-Language
representing	O
set	O
variables	O
as	O
bit	B-Data_Structure
vectors	I-Data_Structure
.	O
</s>
<s>
As	O
shown	O
in	O
the	O
example	O
above	O
,	O
Pascal	B-Application
files	B-Operating_System
are	O
sequences	O
of	O
components	O
.	O
</s>
<s>
In	O
Jensen	O
&	O
Wirth	O
Pascal	B-Application
,	O
strings	O
are	O
represented	O
as	O
packed	O
arrays	O
of	O
chars	O
;	O
they	O
therefore	O
have	O
fixed	O
length	O
and	O
are	O
usually	O
space-padded	O
.	O
</s>
<s>
Pascal	B-Application
supports	O
the	O
use	O
of	O
pointers	O
:	O
</s>
<s>
To	O
create	O
a	O
new	O
record	O
and	O
assign	O
the	O
value	O
10	O
and	O
character	O
A	O
to	O
the	O
fields	O
a	O
and	O
b	O
in	O
the	O
record	O
,	O
and	O
to	O
initialise	O
the	O
pointer	O
c	B-Language
to	O
the	O
null	O
pointer	O
(	O
"	O
NIL	O
"	O
in	O
Pascal	B-Application
)	O
,	O
the	O
statements	O
would	O
be	O
:	O
</s>
<s>
Linked	B-Data_Structure
lists	I-Data_Structure
,	O
stacks	B-Application
and	O
queues	B-Application
can	O
be	O
created	O
by	O
including	O
a	O
pointer	O
type	O
field	O
(	O
c	B-Language
)	O
in	O
the	O
record	O
.	O
</s>
<s>
Unlike	O
many	O
languages	O
that	O
feature	O
pointers	O
,	O
Pascal	B-Application
only	O
allows	O
pointers	O
to	O
reference	O
dynamically	O
created	O
variables	O
that	O
are	O
anonymous	O
,	O
and	O
does	O
not	O
allow	O
them	O
to	O
reference	O
standard	O
static	O
or	O
local	O
variables	O
.	O
</s>
<s>
This	O
helps	O
eliminate	O
the	O
type	O
security	O
issues	O
inherent	O
with	O
other	O
pointer	O
implementations	O
,	O
particularly	O
those	O
used	O
for	O
PL/I	B-Language
or	O
C	B-Language
.	O
It	O
also	O
removes	O
some	O
risks	O
caused	O
by	O
dangling	B-Error_Name
pointers	I-Error_Name
,	O
but	O
the	O
ability	O
to	O
dynamically	O
deallocate	O
referenced	O
space	O
by	O
using	O
the	O
dispose	O
function	O
(	O
which	O
has	O
the	O
same	O
effect	O
as	O
the	O
free	O
library	B-Library
function	I-Library
found	O
in	O
C	B-Language
)	O
means	O
that	O
the	O
risk	O
of	O
dangling	B-Error_Name
pointers	I-Error_Name
has	O
not	O
been	O
eliminated	O
as	O
it	O
has	O
in	O
languages	O
such	O
as	O
Java	B-Language
and	O
C#	B-Application
,	O
which	O
provide	O
automatic	B-General_Concept
garbage	I-General_Concept
collection	I-General_Concept
(	O
but	O
which	O
do	O
not	O
eliminate	O
the	O
related	O
problem	O
of	O
memory	B-Error_Name
leaks	I-Error_Name
)	O
.	O
</s>
<s>
Pascal	B-Application
is	O
a	O
structured	B-Language
programming	I-Language
language	O
,	O
meaning	O
that	O
the	O
flow	O
of	O
control	O
is	O
structured	B-Language
into	O
standard	O
statements	O
,	O
usually	O
without	O
'	O
goto	O
 '	O
commands	O
.	O
</s>
<s>
Pascal	B-Application
structures	O
programs	O
into	O
procedures	O
and	O
functions	O
.	O
</s>
<s>
This	O
ordering	O
requirement	O
was	O
originally	O
intended	O
to	O
allow	O
efficient	O
single-pass	B-Language
compilation	I-Language
.	O
</s>
<s>
However	O
,	O
in	O
some	O
dialects	O
(	O
such	O
as	O
Delphi	B-Language
)	O
the	O
strict	O
ordering	O
requirement	O
of	O
declaration	O
sections	O
has	O
been	O
relaxed	O
.	O
</s>
<s>
Pascal	B-Application
adopted	O
many	O
language	O
syntax	O
features	O
from	O
the	O
ALGOL	B-Language
language	I-Language
,	O
including	O
the	O
use	O
of	O
a	O
semicolon	O
as	O
a	O
statement	O
separator	O
.	O
</s>
<s>
This	O
is	O
in	O
contrast	O
to	O
other	O
languages	O
,	O
such	O
as	O
PL/I	B-Language
and	O
C	B-Language
,	O
which	O
use	O
the	O
semicolon	O
as	O
a	O
statement	O
terminator	O
.	O
</s>
<s>
The	O
presence	O
of	O
an	O
extra	O
semicolon	O
was	O
not	O
permitted	O
in	O
early	O
versions	O
of	O
Pascal	B-Application
.	O
</s>
<s>
However	O
,	O
the	O
addition	O
of	O
ALGOL-like	B-Language
empty	O
statements	O
in	O
the	O
1973	O
Revised	O
Report	O
and	O
later	O
changes	O
to	O
the	O
language	O
in	O
ISO	O
7185:1983	O
now	O
allow	O
for	O
optional	O
semicolons	O
in	O
most	O
of	O
these	O
cases	O
.	O
</s>
<s>
Several	O
Pascal	B-Application
compilers	B-Language
and	O
interpreters	B-Application
are	O
available	O
for	O
general	O
use	O
:	O
</s>
<s>
Delphi	B-Language
is	O
Embarcadero	O
's	O
(	O
formerly	O
Borland/CodeGear	O
)	O
flagship	O
rapid	O
application	O
development	O
(	O
RAD	O
)	O
product	O
.	O
</s>
<s>
It	O
uses	O
the	O
Object	B-Language
Pascal	I-Language
language	O
(	O
termed	O
'	O
Delphi	B-Language
 '	O
by	O
Borland	O
)	O
,	O
descended	O
from	O
Pascal	B-Application
,	O
to	O
create	O
applications	O
for	O
Windows	B-Application
,	O
macOS	B-Application
,	O
iOS	B-Application
,	O
and	O
Android	B-Application
.	O
</s>
<s>
The	O
.NET	B-Application
support	O
that	O
existed	O
from	O
D8	O
through	O
D2005	O
,	O
D2006	O
,	O
and	O
D2007	O
has	O
been	O
terminated	O
,	O
and	O
replaced	O
by	O
a	O
new	O
language	O
(	O
Prism	B-Language
,	O
which	O
is	O
rebranded	O
Oxygene	B-Language
,	O
see	O
below	O
)	O
that	O
is	O
not	O
fully	O
backward	B-General_Concept
compatible	I-General_Concept
.	O
</s>
<s>
In	O
recent	O
years	O
Unicode	O
support	O
and	O
generics	B-Language
were	O
added	O
(	O
D2009	O
,	O
D2010	O
,	O
Delphi	B-Language
XE	O
)	O
.	O
</s>
<s>
Free	B-Operating_System
Pascal	I-Operating_System
is	O
a	O
cross-platform	B-Operating_System
compiler	B-Language
written	O
in	O
Object	B-Language
Pascal	I-Language
(	O
and	O
is	O
self-hosting	O
)	O
.	O
</s>
<s>
It	O
is	O
aimed	O
at	O
providing	O
a	O
convenient	O
and	O
powerful	O
compiler	B-Language
,	O
both	O
able	O
to	O
compile	B-Language
legacy	O
applications	O
and	O
to	O
be	O
the	O
means	O
to	O
develop	O
new	O
ones	O
.	O
</s>
<s>
It	O
is	O
distributed	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
(	O
GNU	B-License
GPL	I-License
)	O
,	O
while	O
packages	O
and	O
runtime	O
library	B-Library
come	O
under	O
a	O
modified	O
GNU	B-Application
Lesser	I-Application
General	I-Application
Public	I-Application
License	I-Application
(	O
GNU	B-Application
LGPL	I-Application
)	O
.	O
</s>
<s>
In	O
addition	O
to	O
compatibility	O
modes	O
for	O
Turbo	B-Application
Pascal	I-Application
,	O
Delphi	B-Language
,	O
and	O
Mac	O
Pascal	B-Application
,	O
it	O
has	O
its	O
own	O
procedural	B-Application
and	O
object-oriented	B-Language
syntax	O
modes	O
with	O
support	O
for	O
extended	O
features	O
such	O
as	O
operator	O
overloading	O
.	O
</s>
<s>
It	O
supports	O
many	O
platforms	O
and	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
Turbo51	B-Language
is	O
a	O
free	B-Operating_System
Pascal	I-Operating_System
compiler	I-Operating_System
for	O
the	O
Intel	B-Architecture
8051	I-Architecture
family	O
of	O
microcontrollers	O
,	O
with	O
Turbo	O
Pascal7	O
syntax	O
.	O
</s>
<s>
Oxygene	B-Language
(	O
formerly	O
named	O
Chrome	B-Language
)	O
is	O
an	O
Object	B-Language
Pascal	I-Language
compiler	B-Language
for	O
the	O
.NET	B-Application
and	O
Mono	B-Application
platforms	I-Application
.	O
</s>
<s>
It	O
was	O
created	O
and	O
is	O
sold	O
by	O
RemObjects	O
Software	O
,	O
and	O
sold	O
for	O
a	O
while	O
by	O
Embarcadero	O
as	O
the	O
backend	O
compiler	B-Language
of	O
Prism	B-Language
.	O
</s>
<s>
Kylix	B-Application
was	O
a	O
descendant	O
of	O
Delphi	B-Language
,	O
with	O
support	O
for	O
the	O
Linux	B-Application
operating	I-Application
system	I-Application
and	O
an	O
improved	O
object	O
library	B-Library
.	O
</s>
<s>
Compiler	B-Language
and	O
IDE	B-Application
are	O
available	O
now	O
for	O
non-commercial	O
use	O
.	O
</s>
<s>
GNU	B-Language
Pascal	I-Language
Compiler	B-Language
(	O
GPC	O
)	O
is	O
the	O
Pascal	B-Application
compiler	B-Language
of	O
the	O
GNU	B-Application
Compiler	I-Application
Collection	I-Application
(	O
GCC	B-Application
)	O
.	O
</s>
<s>
The	O
compiler	B-Language
is	O
written	O
in	O
C	B-Language
,	O
the	O
runtime	O
library	B-Library
mostly	O
in	O
Pascal	B-Application
.	O
</s>
<s>
Distributed	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
,	O
it	O
runs	O
on	O
many	O
platforms	O
and	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
It	O
supports	O
the	O
ANSI/ISO	O
standard	O
languages	O
and	O
has	O
partial	O
Turbo	B-Application
Pascal	I-Application
dialect	O
support	O
.	O
</s>
<s>
Support	O
for	O
Borland	B-Language
Delphi	I-Language
and	O
other	O
language	O
variants	O
is	O
quite	O
limited	O
.	O
</s>
<s>
There	O
is	O
some	O
support	O
for	O
Mac-pascal	O
,	O
however	O
.	O
</s>
<s>
Virtual	B-Application
Pascal	I-Application
was	O
created	O
by	O
Vitaly	O
Miryanov	O
in	O
1995	O
as	O
a	O
native	O
OS/2	B-Application
compiler	B-Language
compatible	O
with	O
Borland	B-Application
Pascal	I-Application
syntax	O
.	O
</s>
<s>
Then	O
,	O
it	O
had	O
been	O
commercially	O
developed	O
by	O
fPrint	O
,	O
adding	O
Win32	B-Library
support	O
,	O
and	O
in	O
2000	O
it	O
became	O
freeware	O
.	O
</s>
<s>
Today	O
it	O
can	O
compile	B-Language
for	O
Win32	B-Library
,	O
OS/2	B-Application
,	O
and	O
Linux	B-Application
,	O
and	O
is	O
mostly	O
compatible	O
with	O
Borland	B-Application
Pascal	I-Application
and	O
Delphi	B-Language
.	O
</s>
<s>
P4	O
compiler	B-Language
,	O
the	O
basis	O
for	O
many	O
subsequent	O
Pascal-implemented-in-Pascal	O
compilers	B-Language
.	O
</s>
<s>
It	O
implements	O
a	O
subset	O
of	O
full	O
Pascal	B-Application
.	O
</s>
<s>
P5	O
compiler	B-Language
is	O
an	O
ISO	B-Application
7185	I-Application
(	O
full	O
Pascal	B-Application
)	O
adaption	O
of	O
P4	O
.	O
</s>
<s>
Turbo	B-Application
Pascal	I-Application
was	O
the	O
dominant	O
Pascal	B-Application
compiler	B-Language
for	O
PCs	O
during	O
the	O
1980s	O
and	O
early	O
1990s	O
,	O
popular	O
both	O
because	O
of	O
its	O
powerful	O
extensions	O
and	O
extremely	O
short	O
compilation	B-Language
times	O
.	O
</s>
<s>
Turbo	B-Application
Pascal	I-Application
was	O
compactly	O
written	O
and	O
could	O
compile	B-Language
,	O
run	O
,	O
and	O
debug	O
all	O
from	O
memory	O
without	O
accessing	O
disk	O
.	O
</s>
<s>
Slow	O
floppy	O
disk	O
drives	O
were	O
common	O
for	O
programmers	O
at	O
the	O
time	O
,	O
further	O
magnifying	O
Turbo	B-Application
Pascal	I-Application
's	O
speed	O
advantage	O
.	O
</s>
<s>
Currently	O
,	O
older	O
versions	O
of	O
Turbo	B-Application
Pascal	I-Application
(	O
up	O
to	O
5.5	O
)	O
are	O
available	O
for	O
free	O
download	O
from	O
Borland	O
's	O
site	O
.	O
</s>
<s>
IP	B-Language
Pascal	I-Language
implements	O
the	O
language	O
"	O
Pascaline	O
"	O
(	O
named	O
after	O
Pascal	B-Application
's	O
calculator	O
)	O
,	O
which	O
is	O
a	O
highly	O
extended	O
Pascal	B-Application
compatible	O
with	O
original	O
Pascal	B-Application
according	O
to	O
ISO	B-Application
7185	I-Application
.	O
</s>
<s>
It	O
features	O
modules	B-Architecture
with	O
namespace	O
control	O
,	O
including	O
parallel	O
tasking	O
modules	B-Architecture
with	O
semaphores	O
,	O
objects	O
,	O
dynamic	B-Data_Structure
arrays	I-Data_Structure
of	O
any	O
dimensions	O
that	O
are	O
allocated	O
at	O
runtime	O
,	O
overloads	O
,	O
overrides	O
,	O
and	O
many	O
other	O
extensions	O
.	O
</s>
<s>
IP	B-Language
Pascal	I-Language
has	O
a	O
built-in	O
portability	O
library	B-Library
that	O
is	O
custom	O
tailored	O
to	O
the	O
Pascal	B-Application
language	I-Application
.	O
</s>
<s>
For	O
example	O
,	O
a	O
standard	O
text	O
output	O
application	O
from	O
1970	O
's	O
original	O
Pascal	B-Application
can	O
be	O
recompiled	B-Language
to	O
work	O
in	O
a	O
window	O
and	O
even	O
have	O
graphical	O
constructs	O
added	O
.	O
</s>
<s>
Pascal-XT	O
was	O
created	O
by	O
Siemens	O
for	O
their	O
mainframe	B-Architecture
operating	B-General_Concept
systems	I-General_Concept
BS2000	B-Application
and	O
SINIX	B-Operating_System
.	O
</s>
<s>
PocketStudio	B-Application
is	O
a	O
Pascal	B-Application
subset	O
compiler	B-Language
and	O
RAD	O
tool	O
for	O
Palm	B-Operating_System
OS	I-Operating_System
and	O
MC68xxx	O
processors	O
with	O
some	O
of	O
its	O
own	O
extensions	O
to	O
assist	O
interfacing	O
with	O
the	O
Palm	B-Operating_System
OS	I-Operating_System
API	B-Application
.	O
</s>
<s>
It	O
resembles	O
Delphi	B-Language
and	O
Lazarus	B-Language
with	O
a	O
visual	O
form	O
designer	O
,	O
an	O
object	O
inspector	O
and	O
a	O
source	B-Application
code	I-Application
editor	I-Application
.	O
</s>
<s>
MIDletPascal	B-Application
–	O
A	O
Pascal	B-Application
compiler	B-Language
and	O
IDE	B-Application
that	O
generates	O
small	O
and	O
fast	O
Java	B-Language
bytecode	O
specifically	O
designed	O
to	O
create	O
software	O
for	O
mobiles	O
.	O
</s>
<s>
Vector	O
Pascal	B-Application
is	O
a	O
language	O
for	O
SIMD	B-Device
instruction	O
sets	O
such	O
as	O
the	O
MMX	O
and	O
the	O
AMD	O
3d	O
Now	O
,	O
supporting	O
all	O
Intel	O
and	O
AMD	O
processors	O
,	O
and	O
Sony	O
's	O
PlayStation	O
2	O
Emotion	O
Engine	O
.	O
</s>
<s>
Morfik	O
Pascal	B-Application
allows	O
the	O
development	O
of	O
Web	O
applications	O
entirely	O
written	O
in	O
Object	B-Language
Pascal	I-Language
(	O
both	O
server	O
and	O
browser	O
side	O
)	O
.	O
</s>
<s>
WDSibyl	O
–	O
Visual	O
Development	O
Environment	O
and	O
Pascal	B-Application
compiler	B-Language
for	O
Win32	B-Library
and	O
OS/2	B-Application
.	O
</s>
<s>
PP	O
Compiler	B-Language
,	O
a	O
compiler	B-Language
for	O
Palm	B-Operating_System
OS	I-Operating_System
that	O
runs	O
directly	O
on	O
the	O
handheld	O
computer	O
.	O
</s>
<s>
CDC	B-Device
6000	I-Device
Pascal	B-Application
compiler	B-Language
is	O
the	O
source	O
code	O
for	O
the	O
first	O
(	O
CDC	B-Device
6000	I-Device
)	O
Pascal	B-Application
compiler	B-Language
.	O
</s>
<s>
AmigaPascal	O
is	O
a	O
free	B-Operating_System
Pascal	I-Operating_System
compiler	I-Operating_System
for	O
the	O
Amiga	O
computer	O
.	O
</s>
<s>
VSI	O
Pascal	B-Application
for	O
OpenVMS	B-Operating_System
(	O
formerly	O
HP	O
Pascal	B-Application
for	O
OpenVMS	B-Operating_System
,	O
Compaq	O
Pascal	B-Application
,	O
DEC	O
Pascal	B-Application
,	O
VAX	O
Pascal	B-Application
and	O
originally	O
VAX-11	O
Pascal	B-Application
)	O
is	O
a	O
Pascal	B-Application
compiler	B-Language
that	O
runs	O
on	O
OpenVMS	B-Operating_System
systems	O
.	O
</s>
<s>
It	O
was	O
also	O
supported	O
under	O
Tru64	B-Operating_System
.	O
</s>
<s>
VSI	O
Pascal	B-Application
for	O
OpenVMS	B-Operating_System
is	O
compatible	O
with	O
ISO/IEC	O
7185:1990	O
Pascal	B-Application
as	O
well	O
some	O
of	O
ISO/IEC	O
10206:1990	O
Extended	O
Pascal	B-Application
,	O
and	O
also	O
includes	O
its	O
own	O
extensions	O
.	O
</s>
<s>
The	O
compiler	B-Language
frontend	O
is	O
implemented	O
in	O
BLISS	B-Language
.	O
</s>
<s>
Stony	O
Brook	O
Pascal+	O
was	O
a	O
16-bit	O
(	O
later	O
32-bit	O
)	O
optimizing	O
compiler	B-Language
for	O
DOS	B-Device
and	O
OS/2	B-Application
,	O
marketed	O
as	O
a	O
direct	O
replacement	O
for	O
Turbo	B-Application
Pascal	I-Application
,	O
but	O
producing	O
code	O
that	O
executed	O
at	O
least	O
twice	O
as	O
fast	O
.	O
</s>
<s>
Dev-Pascal	B-Language
is	O
a	O
Pascal	B-Application
IDE	B-Application
that	O
was	O
designed	O
in	O
Borland	B-Language
Delphi	I-Language
and	O
which	O
supports	O
Free	B-Operating_System
Pascal	I-Operating_System
and	O
GNU	B-Language
Pascal	I-Language
as	O
backends	O
.	O
</s>
<s>
Lazarus	B-Language
is	O
a	O
free	O
Delphi-like	O
visual	O
cross-platform	B-Operating_System
IDE	B-Application
for	O
rapid	O
application	O
development	O
(	O
RAD	O
)	O
.	O
</s>
<s>
Based	O
on	O
Free	B-Operating_System
Pascal	I-Operating_System
,	O
Lazarus	B-Language
is	O
available	O
for	O
numerous	O
platforms	O
including	O
Linux	B-Application
,	O
FreeBSD	B-Operating_System
,	O
macOS	B-Application
and	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
WOL	O
Library	B-Library
for	O
creating	O
GUI	O
applications	O
with	O
the	O
Free	B-Operating_System
Pascal	I-Operating_System
Compiler	I-Operating_System
.	O
</s>
<s>
In	O
1989	O
,	O
ISO	B-Application
7185	I-Application
was	O
revised	O
(	O
ISO	O
7185:1990	O
)	O
to	O
correct	O
various	O
errors	O
and	O
ambiguities	O
found	O
in	O
the	O
original	O
document	O
.	O
</s>
<s>
The	O
ISO	B-Application
7185	I-Application
was	O
stated	O
to	O
be	O
a	O
clarification	O
of	O
Wirth	O
's	O
1974	O
language	O
as	O
detailed	O
by	O
the	O
User	O
Manual	O
and	O
Report	O
[	O
Jensen	O
and	O
Wirth ]	O
,	O
but	O
was	O
also	O
notable	O
for	O
adding	O
"	O
Conformant	O
Array	O
Parameters	O
"	O
as	O
a	O
level	O
1	O
to	O
the	O
standard	O
,	O
level	O
0	O
being	O
Pascal	B-Application
without	O
conformant	O
arrays	O
.	O
</s>
<s>
This	O
addition	O
was	O
made	O
at	O
the	O
request	O
of	O
C	B-Language
.	O
A	O
.	O
R	O
.	O
Hoare	O
,	O
and	O
with	O
the	O
approval	O
of	O
Niklaus	O
Wirth	O
.	O
</s>
<s>
The	O
precipitating	O
cause	O
was	O
that	O
Hoare	O
wanted	O
to	O
create	O
a	O
Pascal	B-Application
version	O
of	O
the	O
(	O
NAG	O
)	O
Numerical	O
Algorithms	O
Library	B-Library
,	O
which	O
had	O
originally	O
been	O
written	O
in	O
FORTRAN	B-Application
,	O
and	O
found	O
that	O
it	O
was	O
not	O
possible	O
to	O
do	O
so	O
without	O
an	O
extension	O
that	O
would	O
allow	O
array	O
parameters	O
of	O
varying	O
size	O
.	O
</s>
<s>
Similar	O
considerations	O
motivated	O
the	O
inclusion	O
in	O
ISO	B-Application
7185	I-Application
of	O
the	O
facility	O
to	O
specify	O
the	O
parameter	O
types	O
of	O
procedural	B-Application
and	O
functional	O
parameters	O
.	O
</s>
<s>
Niklaus	O
Wirth	O
himself	O
referred	O
to	O
the	O
1974	O
language	O
as	O
"	O
the	O
Standard	O
"	O
,	O
for	O
example	O
,	O
to	O
differentiate	O
it	O
from	O
the	O
machine	O
specific	O
features	O
of	O
the	O
CDC	B-Device
6000	I-Device
compiler	B-Language
.	O
</s>
<s>
This	O
language	O
was	O
documented	O
in	O
The	O
Pascal	B-Application
Report	O
,	O
the	O
second	O
part	O
of	O
the	O
"	O
Pascal	B-Application
users	O
manual	O
and	O
report	O
"	O
.	O
</s>
<s>
On	O
the	O
large	O
machines	O
(	O
mainframes	B-Architecture
and	O
minicomputers	B-Architecture
)	O
Pascal	B-Application
originated	O
on	O
,	O
the	O
standards	O
were	O
generally	O
followed	O
.	O
</s>
<s>
On	O
the	O
IBM	B-Device
PC	I-Device
,	O
they	O
were	O
not	O
.	O
</s>
<s>
On	O
IBMPCs	B-Device
,	O
the	O
Borland	O
standards	O
Turbo	B-Application
Pascal	I-Application
and	O
Delphi	B-Language
have	O
the	O
greatest	O
number	O
of	O
users	O
.	O
</s>
<s>
Thus	O
,	O
it	O
is	O
typically	O
important	O
to	O
understand	O
whether	O
a	O
particular	O
implementation	O
corresponds	O
to	O
the	O
original	O
Pascal	B-Application
language	I-Application
,	O
or	O
a	O
Borland	O
dialect	O
of	O
it	O
.	O
</s>
<s>
The	O
IBMPC	B-Device
versions	O
of	O
the	O
language	O
began	O
to	O
differ	O
with	O
the	O
advent	O
of	O
UCSD	B-Language
Pascal	I-Language
,	O
an	O
interpreted	O
implementation	O
that	O
featured	O
several	O
extensions	O
to	O
the	O
language	O
,	O
along	O
with	O
several	O
omissions	O
and	O
changes	O
.	O
</s>
<s>
As	O
of	O
2019	O
,	O
Support	O
of	O
Extended	O
Pascal	B-Application
in	O
FreePascal	B-Operating_System
Compiler	B-Language
is	O
planned	O
.	O
</s>
<s>
Niklaus	O
Wirth	O
's	O
Zürich	O
version	O
of	O
Pascal	B-Application
was	O
issued	O
outside	O
ETH	O
in	O
two	O
basic	O
forms	O
:	O
the	O
CDC	B-Device
6000	I-Device
compiler	B-Language
source	O
,	O
and	O
a	O
porting	O
kit	O
called	O
Pascal-P	O
system	O
.	O
</s>
<s>
The	O
Pascal-P	O
compiler	B-Language
left	O
out	O
several	O
features	O
of	O
the	O
full	O
language	O
that	O
were	O
not	O
required	O
to	O
bootstrap	O
the	O
compiler	B-Language
.	O
</s>
<s>
For	O
example	O
,	O
procedures	O
and	O
functions	O
used	O
as	O
parameters	O
,	O
undiscriminated	O
variant	O
records	O
,	O
packing	O
,	O
dispose	O
,	O
interprocedural	O
gotos	O
and	O
other	O
features	O
of	O
the	O
full	O
compiler	B-Language
were	O
omitted	O
.	O
</s>
<s>
UCSD	B-Language
Pascal	I-Language
,	O
under	O
Professor	O
Kenneth	O
Bowles	O
,	O
was	O
based	O
on	O
the	O
Pascal-P2	B-Application
kit	O
,	O
and	O
consequently	O
shared	O
several	O
of	O
the	O
Pascal-P	O
language	O
restrictions	O
.	O
</s>
<s>
UCSD	B-Language
Pascal	I-Language
was	O
later	O
adopted	O
as	O
Apple	B-Operating_System
Pascal	I-Operating_System
,	O
and	O
continued	O
through	O
several	O
versions	O
there	O
.	O
</s>
<s>
Although	O
UCSD	B-Language
Pascal	I-Language
actually	O
expanded	O
the	O
subset	O
Pascal	B-Application
in	O
the	O
Pascal-P	O
kit	O
by	O
adding	O
back	O
standard	O
Pascal	B-Application
constructs	O
,	O
it	O
was	O
still	O
not	O
a	O
complete	O
standard	O
installation	O
of	O
Pascal	B-Application
.	O
</s>
<s>
In	O
the	O
early	O
1990s	O
,	O
Alan	O
Burns	O
and	O
Geoff	O
Davies	O
developed	O
Pascal-FC	O
,	O
an	O
extension	O
to	O
Pl/0	O
(	O
from	O
the	O
Niklaus	O
 '	O
book	O
Algorithms	O
+	O
Data	B-General_Concept
Structures	I-General_Concept
=	O
Programs	O
)	O
.	O
</s>
<s>
Several	O
constructs	O
were	O
added	O
to	O
use	O
Pascal-FC	O
as	O
a	O
teaching	O
tool	O
for	O
Concurrent	O
Programming	O
(	O
such	O
as	O
semaphores	O
,	O
monitors	O
,	O
channels	O
,	O
remote-invocation	O
and	O
resources	O
)	O
.	O
</s>
<s>
To	O
be	O
able	O
to	O
demonstrate	O
concurrency	O
,	O
the	O
compiler	B-Language
output	O
(	O
a	O
kind	O
of	O
P-code	B-Language
)	O
could	O
then	O
be	O
executed	O
on	O
a	O
virtual	O
machine	O
.	O
</s>
<s>
Borland	O
's	O
Turbo	B-Application
Pascal	I-Application
,	O
written	O
by	O
Anders	O
Hejlsberg	O
,	O
was	O
written	O
in	O
assembly	B-Language
language	I-Language
independent	O
of	O
UCSD	O
and	O
the	O
Zürich	O
compilers	B-Language
.	O
</s>
<s>
However	O
,	O
it	O
adopted	O
much	O
of	O
the	O
same	O
subset	O
and	O
extensions	O
as	O
the	O
UCSD	O
compiler	B-Language
.	O
</s>
<s>
This	O
is	O
probably	O
because	O
the	O
UCSD	O
system	O
was	O
the	O
most	O
common	O
Pascal	B-Application
system	O
suitable	O
for	O
developing	O
applications	O
on	O
the	O
resource-limited	O
microprocessor	O
systems	O
available	O
at	O
that	O
time	O
.	O
</s>
<s>
The	O
shrink-wrapped	O
Turbo	B-Application
Pascal	I-Application
version	O
3	O
and	O
later	O
incarnations	O
,	O
including	O
Borland	O
's	O
Object	B-Language
Pascal	I-Language
and	O
Delphi	B-Language
and	O
non-Borland	O
near-compatibles	O
became	O
popular	O
with	O
programmers	O
including	O
shareware	O
authors	O
,	O
and	O
so	O
the	O
SWAG	O
library	B-Library
of	O
Pascal	B-Application
code	O
features	O
a	O
large	O
amount	O
of	O
code	O
written	O
with	O
such	O
versions	O
as	O
Delphi	B-Language
in	O
mind	O
.	O
</s>
<s>
Software	O
products	O
(	O
compilers	B-Language
,	O
and	O
IDE/Rapid	O
Application	O
Development	O
(	O
RAD	O
)	O
)	O
in	O
this	O
category	O
:	O
</s>
<s>
Turbo	B-Application
Pascal	I-Application
–	O
"	O
TURBO.EXE	B-Application
"	O
up	O
to	O
version	O
7	O
,	O
and	O
Turbo	B-Application
Pascal	I-Application
for	O
Windows	B-Application
(	O
"	O
TPW	O
"	O
)	O
and	O
Turbo	B-Application
Pascal	I-Application
for	O
Macintosh	B-Device
.	O
</s>
<s>
Pure	O
Pascal	B-Application
and	O
HiSPeed	O
Pascal	B-Application
2	O
Pascal	B-Application
language	I-Application
Environment	O
for	O
the	O
Atari	O
ST	O
range	O
of	O
computers	O
.	O
</s>
<s>
Borland	B-Application
Pascal	I-Application
7	I-Application
–	O
A	O
professional	O
version	O
of	O
Turbo	B-Application
Pascal	I-Application
line	O
which	O
targeted	O
both	O
DOS	B-Device
and	O
Windows	B-Application
.	O
</s>
<s>
Object	B-Language
Pascal	I-Language
–	O
an	O
extension	O
of	O
the	O
Pascal	B-Application
language	I-Application
that	O
was	O
developed	O
at	O
Apple	O
Computer	O
by	O
a	O
team	O
led	O
by	O
Larry	O
Tesler	O
in	O
consultation	O
with	O
Niklaus	O
Wirth	O
,	O
the	O
inventor	O
of	O
Pascal	B-Application
;	O
its	O
features	O
were	O
added	O
to	O
Borland	O
's	O
Turbo	B-Application
Pascal	I-Application
for	O
Macintosh	B-Device
and	O
in	O
1989	O
for	O
Turbo	B-Application
Pascal	I-Application
5.5	O
for	O
DOS	B-Device
.	O
</s>
<s>
Delphi	B-Language
–	O
Object	B-Language
Pascal	I-Language
is	O
essentially	O
its	O
underlying	O
language	O
.	O
</s>
<s>
Free	B-Operating_System
Pascal	I-Operating_System
compiler	I-Operating_System
(	O
FPC	O
)	O
–	O
Free	B-Operating_System
Pascal	I-Operating_System
adopted	O
the	O
de	O
facto	O
standard	O
dialect	O
of	O
Pascal	B-Application
programmers	O
,	O
Borland	B-Application
Pascal	I-Application
and	O
,	O
later	O
,	O
Delphi	B-Language
.	O
</s>
<s>
Freepascal	B-Operating_System
also	O
supports	O
both	O
ISO	O
standards	O
.	O
</s>
<s>
PascalABC.NET	B-Language
–	O
a	O
new	O
generation	O
Pascal	B-Application
programming	I-Application
language	I-Application
including	O
compiler	B-Language
and	O
IDE	B-Application
.	O
</s>
<s>
Borland	B-Application
Kylix	I-Application
is	O
a	O
compiler	B-Language
and	O
IDE	B-Application
formerly	O
sold	O
by	O
Borland	O
,	O
but	O
later	O
discontinued	O
.	O
</s>
<s>
It	O
is	O
a	O
Linux	B-Application
version	O
of	O
the	O
Borland	B-Language
Delphi	I-Language
software	B-Application
development	I-Application
environment	I-Application
and	O
C++Builder	B-Language
.	O
</s>
<s>
Lazarus	B-Language
–	O
similar	O
to	O
Kylix	B-Application
in	O
function	O
,	O
is	O
a	O
free	O
cross-platform	B-Operating_System
visual	O
IDE	B-Application
for	O
RAD	O
using	O
the	O
Free	B-Operating_System
Pascal	I-Operating_System
compiler	I-Operating_System
,	O
which	O
supports	O
dialects	O
of	O
Object	B-Language
Pascal	I-Language
to	O
varying	O
degrees	O
.	O
</s>
<s>
Virtual	B-Application
Pascal	I-Application
–	O
VP2/1	O
is	O
a	O
fully	O
Borland	B-Application
Pascal	I-Application
–	O
and	O
Borland	B-Language
Delphi	I-Language
–	O
compatible	O
32-bit	O
Pascal	B-Application
compiler	B-Language
for	O
OS/2	B-Application
and	O
Windows	B-Application
32	O
(	O
with	O
a	O
Linux	B-Application
version	O
"	O
on	O
the	O
way	O
"	O
)	O
.	O
</s>
<s>
Sybil	O
is	O
an	O
open	B-Application
source	I-Application
Delphi-like	O
IDE	B-Application
and	O
compiler	B-Language
;	O
implementations	O
include	O
:	O
</s>
<s>
WDSibyl	O
for	O
Microsoft	B-Application
Windows	I-Application
and	O
OS/2	B-Application
,	O
a	O
commercial	O
Borland	B-Application
Pascal	I-Application
compatible	O
environment	O
released	O
by	O
a	O
company	O
named	O
Speedsoft	O
that	O
was	O
later	O
developed	O
into	O
a	O
Delphi-like	O
rapid	O
application	O
development	O
(	O
RAD	O
)	O
environment	O
named	O
Sybil	O
and	O
then	O
open	O
sourced	O
under	O
the	O
GPL	B-License
when	O
that	O
company	O
closed	O
down	O
;	O
</s>
<s>
Open	O
Sybil	O
,	O
which	O
is	O
an	O
ongoing	O
project	O
,	O
an	O
open	B-Application
source	I-Application
tool	O
for	O
OS/2	B-Application
and	O
eCS	O
that	O
was	O
originally	O
based	O
on	O
Speedsoft	O
's	O
WDsybl	O
Sibyl	O
Portable	O
Component	O
Classes	O
(	O
SPCC	O
)	O
and	O
Sibyl	O
Visual	O
Development	O
Tool	O
(	O
SVDE	O
)	O
sources	O
,	O
but	O
now	O
its	O
core	O
is	O
IBM	B-Device
System	I-Device
Object	I-Device
Model	I-Device
(	O
SOM	O
)	O
,	O
WPS	O
and	O
OpenDoc	B-Application
.	O
</s>
<s>
Pascal	B-Application
generated	O
a	O
wide	O
variety	O
of	O
responses	O
in	O
the	O
computing	O
community	O
,	O
both	O
critical	O
and	O
complimentary	O
.	O
</s>
<s>
While	O
very	O
popular	O
in	O
the	O
1980s	O
and	O
early	O
1990s	O
,	O
implementations	O
of	O
Pascal	B-Application
that	O
closely	O
followed	O
Wirth	O
's	O
initial	O
definition	O
of	O
the	O
language	O
were	O
widely	O
criticized	O
as	O
being	O
unsuitable	O
for	O
use	O
outside	O
teaching	O
.	O
</s>
<s>
Brian	O
Kernighan	O
,	O
who	O
popularized	O
the	O
C	B-Language
language	I-Language
,	O
outlined	O
his	O
most	O
notable	O
criticisms	O
of	O
Pascal	B-Application
as	O
early	O
as	O
1981	O
in	O
his	O
article	O
"	O
Why	O
Pascal	B-Application
is	O
Not	O
My	O
Favorite	O
Programming	O
Language	O
"	O
.	O
</s>
<s>
This	O
made	O
it	O
unfeasible	O
to	O
write	O
,	O
for	O
example	O
,	O
a	O
sorting	O
library	B-Library
.	O
</s>
<s>
Kernighan	O
also	O
criticized	O
the	O
unpredictable	O
order	O
of	O
evaluation	O
of	O
boolean	O
expressions	O
,	O
poor	O
library	B-Library
support	O
,	O
and	O
lack	O
of	O
static	B-General_Concept
variables	I-General_Concept
,	O
and	O
raised	O
a	O
number	O
of	O
smaller	O
issues	O
.	O
</s>
<s>
More	O
general	O
complaints	O
from	O
other	O
sources	O
noted	O
that	O
the	O
scope	O
of	O
declarations	O
was	O
not	O
clearly	O
defined	O
in	O
the	O
original	O
language	O
definition	O
,	O
which	O
sometimes	O
had	O
serious	O
consequences	O
when	O
using	O
forward	O
declarations	O
to	O
define	O
pointer	O
types	O
,	O
or	O
when	O
record	O
declarations	O
led	O
to	O
mutual	O
recursion	O
,	O
or	O
when	O
an	O
identifier	O
may	O
or	O
may	O
not	O
have	O
been	O
used	O
in	O
an	O
enumeration	B-Language
list	O
.	O
</s>
<s>
Another	O
difficulty	O
was	O
that	O
,	O
like	O
ALGOL	B-Language
60	I-Language
,	O
the	O
language	O
did	O
not	O
allow	O
procedures	O
or	O
functions	O
passed	O
as	O
parameters	O
to	O
predefine	O
the	O
expected	O
type	O
of	O
their	O
parameters	O
.	O
</s>
<s>
Despite	O
initial	O
criticisms	O
,	O
Pascal	B-Application
continued	O
to	O
evolve	O
,	O
and	O
most	O
of	O
Kernighan	O
's	O
points	O
do	O
not	O
apply	O
to	O
versions	O
of	O
the	O
language	O
which	O
were	O
enhanced	O
to	O
be	O
suitable	O
for	O
commercial	O
product	O
development	O
,	O
such	O
as	O
Borland	O
's	O
Turbo	B-Application
Pascal	I-Application
.	O
</s>
<s>
As	O
Kernighan	O
predicted	O
in	O
his	O
article	O
,	O
most	O
of	O
the	O
extensions	O
to	O
fix	O
these	O
issues	O
were	O
incompatible	O
from	O
compiler	B-Language
to	O
compiler	B-Language
.	O
</s>
<s>
Extended	O
Pascal	B-Application
addresses	O
many	O
of	O
these	O
early	O
criticisms	O
.	O
</s>
<s>
It	O
supports	O
variable-length	O
strings	O
,	O
variable	O
initialization	O
,	O
separate	O
compilation	B-Language
,	O
short-circuit	O
boolean	O
operators	O
,	O
and	O
default	O
(	O
otherwise	O
)	O
clauses	O
for	O
case	O
statements	O
.	O
</s>
