<s>
A	O
fourth-generation	B-Language
programming	I-Language
language	I-Language
(	O
4GL	B-Language
)	O
is	O
any	O
computer	O
programming	O
language	O
that	O
belongs	O
to	O
a	O
class	O
of	O
languages	O
envisioned	O
as	O
an	O
advancement	O
upon	O
third-generation	O
programming	O
languages	O
(	O
3GL	O
)	O
.	O
</s>
<s>
Each	O
of	O
the	O
programming	O
language	O
generations	O
aims	O
to	O
provide	O
a	O
higher	O
level	O
of	O
abstraction	B-Architecture
of	O
the	O
internal	O
computer	B-Architecture
hardware	I-Architecture
details	O
,	O
making	O
the	O
language	O
more	O
programmer-friendly	O
,	O
powerful	O
,	O
and	O
versatile	O
.	O
</s>
<s>
While	O
the	O
definition	O
of	O
4GL	B-Language
has	O
changed	O
over	O
time	O
,	O
it	O
can	O
be	O
typified	O
by	O
operating	O
more	O
with	O
large	O
collections	O
of	O
information	O
at	O
once	O
rather	O
than	O
focusing	O
on	O
just	O
bits	O
and	O
bytes	B-Application
.	O
</s>
<s>
Languages	O
claimed	O
to	O
be	O
4GL	B-Language
may	O
include	O
support	O
for	O
database	O
management	O
,	O
report	B-General_Concept
generation	I-General_Concept
,	O
mathematical	O
optimization	O
,	O
GUI	O
development	O
,	O
or	O
web	O
development	O
.	O
</s>
<s>
Some	O
researchers	O
state	O
that	O
4GLs	B-Language
are	O
a	O
subset	O
of	O
domain-specific	B-Language
languages	I-Language
.	O
</s>
<s>
The	O
concept	O
of	O
4GL	B-Language
was	O
developed	O
from	O
the	O
1970s	O
through	O
the	O
1990s	O
,	O
overlapping	O
most	O
of	O
the	O
development	O
of	O
3GL	O
,	O
with	O
4GLs	B-Language
identified	O
as	O
"	O
non-procedural	O
"	O
or	O
"	O
program-generating	O
"	O
languages	O
,	O
contrasted	O
with	O
3GLs	O
being	O
algorithmic	O
or	O
procedural	O
languages	O
.	O
</s>
<s>
While	O
3GLs	O
like	O
C	B-Language
,	O
C++	B-Language
,	O
C#	B-Application
,	O
Java	B-Language
,	O
and	O
JavaScript	B-Language
remain	O
popular	O
for	O
a	O
wide	O
variety	O
of	O
uses	O
,	O
4GLs	B-Language
as	O
originally	O
defined	O
found	O
uses	O
focused	O
on	O
databases	O
,	O
reports	O
,	O
and	O
websites	O
.	O
</s>
<s>
Some	O
advanced	O
3GLs	O
like	O
Python	B-Language
,	O
Ruby	B-Language
,	O
and	O
Perl	B-Language
combine	O
some	O
4GL	B-Language
abilities	O
within	O
a	O
general-purpose	O
3GL	O
environment	O
,	O
and	O
libraries	B-Library
with	O
4GL-like	O
features	O
have	O
been	O
developed	O
as	O
add-ons	O
for	O
most	O
popular	O
3GLs	O
,	O
producing	O
languages	O
that	O
are	O
a	O
mix	O
of	O
3GL	O
and	O
4GL	B-Language
,	O
blurring	O
the	O
distinction	O
.	O
</s>
<s>
Though	O
used	O
earlier	O
in	O
papers	O
and	O
discussions	O
,	O
the	O
term	O
4GL	B-Language
was	O
first	O
used	O
formally	O
by	O
James	O
Martin	O
in	O
his	O
1981	O
book	O
Applications	O
Development	O
Without	O
Programmers	B-Application
to	O
refer	O
to	O
non-procedural	O
,	O
high-level	O
specification	B-Application
languages	I-Application
.	O
</s>
<s>
In	O
some	O
primitive	O
way	O
,	O
early	O
4GLs	B-Language
were	O
included	O
in	O
the	O
Informatics	O
MARK-IV	B-Language
(	O
1967	O
)	O
product	O
and	O
Sperry	O
's	O
MAPPER	B-Language
(	O
1969	O
internal	O
use	O
,	O
1979	O
release	O
)	O
.	O
</s>
<s>
The	O
motivations	O
for	O
the	O
'	O
4GL	B-Language
 '	O
inception	O
and	O
continued	O
interest	O
are	O
several	O
.	O
</s>
<s>
Just	O
as	O
the	O
3GL	O
offered	O
greater	O
power	O
to	O
the	O
programmer	B-Application
,	O
so	O
too	O
did	O
the	O
4GL	B-Language
open	O
up	O
the	O
development	O
environment	O
to	O
a	O
wider	O
population	O
.	O
</s>
<s>
The	O
early	O
input	O
scheme	O
for	O
the	O
4GL	B-Language
supported	O
entry	O
of	O
data	O
within	O
the	O
72-character	O
limit	O
of	O
the	O
punched	O
card	O
(	O
8	O
bytes	B-Application
used	O
for	O
sequencing	O
)	O
where	O
a	O
card	O
's	O
tag	O
would	O
identify	O
the	O
type	O
or	O
function	O
.	O
</s>
<s>
With	O
judicious	O
use	O
of	O
a	O
few	O
cards	O
,	O
the	O
4GL	B-Language
deck	O
could	O
offer	O
a	O
wide	O
variety	O
of	O
processing	O
and	O
reporting	O
capability	O
whereas	O
the	O
equivalent	O
functionality	O
coded	O
in	O
a	O
3GL	O
could	O
subsume	O
,	O
perhaps	O
,	O
a	O
whole	O
box	O
or	O
more	O
of	O
cards	O
.	O
</s>
<s>
The	O
72-character	O
format	O
continued	O
for	O
a	O
while	O
as	O
hardware	B-Architecture
progressed	O
to	O
larger	O
memory	O
and	O
terminal	O
interfaces	O
.	O
</s>
<s>
An	O
example	O
of	O
this	O
is	O
described	O
on	O
the	O
Nomad	B-Application
page	O
.	O
</s>
<s>
Another	O
example	O
of	O
Nomad	B-Application
's	O
power	O
is	O
illustrated	O
by	O
Nicholas	O
Rawlings	O
in	O
his	O
comments	O
for	O
the	O
Computer	O
History	O
Museum	O
about	O
NCSS	O
(	O
see	O
citation	O
below	O
)	O
.	O
</s>
<s>
He	O
reports	O
that	O
James	O
Martin	O
asked	O
Rawlings	O
for	O
a	O
Nomad	B-Application
solution	O
to	O
a	O
standard	O
problem	O
Martin	O
called	O
the	O
Engineer	O
's	O
Problem	O
:	O
"	O
give	O
6%	O
raises	O
to	O
engineers	O
whose	O
job	O
ratings	O
had	O
an	O
average	O
of	O
7	O
or	O
better.	O
"	O
</s>
<s>
Martin	O
provided	O
a	O
"	O
dozen	O
pages	O
of	O
COBOL	B-Application
,	O
and	O
then	O
just	O
a	O
page	O
or	O
two	O
of	O
Mark	B-Language
IV	I-Language
,	O
from	O
Informatics.	O
"	O
</s>
<s>
The	O
development	O
of	O
the	O
4GL	B-Language
was	O
influenced	O
by	O
several	O
factors	O
,	O
with	O
the	O
hardware	B-Architecture
and	O
operating	O
system	O
constraints	O
having	O
a	O
large	O
weight	O
.	O
</s>
<s>
When	O
the	O
4GL	B-Language
was	O
first	O
introduced	O
,	O
a	O
disparate	O
mix	O
of	O
hardware	B-Architecture
and	O
operating	O
systems	O
mandated	O
custom	O
application	O
development	O
support	O
that	O
was	O
specific	O
to	O
the	O
system	O
in	O
order	O
to	O
ensure	O
sales	O
.	O
</s>
<s>
One	O
example	O
is	O
the	O
MAPPER	B-Language
system	O
developed	O
by	O
Sperry	O
.	O
</s>
<s>
MARK-IV	B-Language
is	O
now	O
known	O
as	O
VISION:BUILDER	B-Language
and	O
is	O
offered	O
by	O
Computer	O
Associates	O
.	O
</s>
<s>
Santa	O
Fe	O
railroad	O
used	O
MAPPER	B-Language
to	O
develop	O
a	O
system	O
,	O
in	O
a	O
project	O
that	O
was	O
an	O
early	O
example	O
of	O
4GL	B-Language
,	O
rapid	O
prototyping	O
,	O
and	O
programming	B-General_Concept
by	I-General_Concept
users	I-General_Concept
.	O
</s>
<s>
The	O
idea	O
was	O
that	O
it	O
was	O
easier	O
to	O
teach	O
railroad	O
experts	O
to	O
use	O
MAPPER	B-Language
than	O
to	O
teach	O
programmers	B-Application
the	O
"	O
intricacies	O
of	O
railroad	O
operations	O
"	O
.	O
</s>
<s>
One	O
of	O
the	O
early	O
(	O
and	O
portable	O
)	O
languages	O
that	O
had	O
4GL	B-Language
properties	O
was	O
Ramis	B-Language
developed	O
by	O
Gerald	O
C	B-Language
.	O
Cohen	O
at	O
Mathematica	B-Language
,	O
a	O
mathematical	O
software	O
company	O
.	O
</s>
<s>
Cohen	O
left	O
Mathematica	B-Language
and	O
founded	O
Information	O
Builders	O
to	O
create	O
a	O
similar	O
reporting-oriented	O
4GL	B-Language
,	O
called	O
FOCUS	O
.	O
</s>
<s>
Later	O
4GL	B-Language
types	O
are	O
tied	O
to	O
a	O
database	O
system	O
and	O
are	O
far	O
different	O
from	O
the	O
earlier	O
types	O
in	O
their	O
use	O
of	O
techniques	O
and	O
resources	O
that	O
have	O
resulted	O
from	O
the	O
general	O
improvement	O
of	O
computing	O
with	O
time	O
.	O
</s>
<s>
An	O
interesting	O
twist	O
to	O
the	O
4GL	B-Language
scene	O
is	O
realization	O
that	O
graphical	O
interfaces	O
and	O
the	O
related	B-General_Concept
reasoning	I-General_Concept
done	O
by	O
the	O
user	O
form	O
a	O
'	O
language	O
 '	O
that	O
is	O
poorly	O
understood	O
.	O
</s>
<s>
A	O
number	O
of	O
different	O
types	O
of	O
4GLs	B-Language
exist	O
:	O
</s>
<s>
Table-driven	O
(	O
codeless	O
)	O
programming	O
,	O
usually	O
running	O
with	O
a	O
runtime	O
framework	O
and	O
libraries	B-Library
.	O
</s>
<s>
Instead	O
of	O
using	O
code	O
,	O
the	O
developer	B-Application
defines	O
their	O
logic	O
by	O
selecting	O
an	O
operation	O
in	O
a	O
pre-defined	O
list	O
of	O
memory	O
or	O
data	O
table	O
manipulation	O
commands	B-Application
.	O
</s>
<s>
In	O
other	O
words	O
,	O
instead	O
of	O
coding	O
,	O
the	O
developer	B-Application
uses	O
table-driven	O
algorithm	O
programming	O
(	O
see	O
also	O
control	B-Application
tables	I-Application
that	O
can	O
be	O
used	O
for	O
this	O
purpose	O
)	O
.	O
</s>
<s>
A	O
good	O
example	O
of	O
this	O
type	O
of	O
4GL	B-Language
language	O
is	O
PowerBuilder	B-Language
.	O
</s>
<s>
They	O
usually	O
offer	O
integration	O
with	O
lower	O
level	O
DLLs	O
generated	O
from	O
a	O
typical	O
3GL	O
for	O
when	O
the	O
need	O
arise	O
for	O
more	O
hardware/OS	O
specific	O
operations	O
.	O
</s>
<s>
More	O
ambitious	O
4GLs	B-Language
(	O
sometimes	O
termed	O
fourth	O
generation	O
environments	O
)	O
attempt	O
to	O
automatically	O
generate	O
whole	O
systems	O
from	O
the	O
outputs	O
of	O
CASE	B-Application
tools	O
,	O
specifications	O
of	O
screens	O
and	O
reports	O
,	O
and	O
possibly	O
also	O
the	O
specification	O
of	O
some	O
additional	O
processing	O
logic	O
.	O
</s>
<s>
Data	B-General_Concept
management	I-General_Concept
4GLs	B-Language
such	O
as	O
SAS	B-Language
,	O
SPSS	B-Algorithm
,	O
and	O
Stata	B-Algorithm
provide	O
sophisticated	O
coding	O
commands	B-Application
for	O
data	O
manipulation	O
,	O
file	O
reshaping	O
,	O
case	B-Application
selection	O
,	O
and	O
data	O
documentation	O
in	O
the	O
preparation	O
of	O
data	O
for	O
statistical	O
analysis	O
and	O
reporting	O
.	O
</s>
<s>
So-called	O
"	O
XTalk	O
"	O
languages	O
,	O
developed	O
initially	O
with	O
Apple	O
's	O
Hypercard	B-Application
in	O
1987	O
.	O
</s>
<s>
Hypercard	B-Application
was	O
the	O
progenitor	O
of	O
more	O
modern	O
and	O
powerful	O
programs	O
such	O
as	O
SuperCard	O
,	O
Toolbook	O
and	O
LiveCode	B-Application
.	O
</s>
<s>
Some	O
4GLs	B-Language
have	O
integrated	O
tools	O
that	O
allow	O
for	O
the	O
easy	O
specification	O
of	O
all	O
the	O
required	O
information	O
:	O
</s>
<s>
James	O
Martin	O
's	O
version	O
of	O
data	B-Application
engineering	I-Application
systems	O
development	O
methodology	O
was	O
automated	O
to	O
allow	O
the	O
input	O
of	O
the	O
results	O
of	O
system	O
analysis	O
and	O
design	O
in	O
the	O
form	O
of	O
data	B-Application
flow	I-Application
diagrams	I-Application
,	O
entity	B-Architecture
relationship	I-Architecture
diagrams	I-Architecture
,	O
entity	O
life	O
history	O
diagrams	O
etc.	O
,	O
from	O
which	O
hundreds	O
of	O
thousands	O
of	O
lines	O
of	O
COBOL	B-Application
would	O
be	O
generated	O
overnight	O
.	O
</s>
<s>
More	O
recently	O
Oracle	B-Application
Corporation	I-Application
's	O
Oracle	B-Application
Designer	I-Application
and	O
Oracle	B-Application
Developer	I-Application
Suite	I-Application
4GL	B-Language
products	O
could	O
be	O
integrated	O
to	O
produce	O
database	O
definitions	O
and	O
the	O
forms	O
and	O
reports	O
programs	O
.	O
</s>
<s>
In	O
the	O
twenty-first	O
century	O
,	O
4GL	B-Language
systems	O
have	O
emerged	O
as	O
"	B-Architecture
low	I-Architecture
code	I-Architecture
"	I-Architecture
environments	I-Architecture
or	I-Architecture
platforms	I-Architecture
for	O
the	O
problem	O
of	O
rapid	O
application	O
development	O
in	O
short	O
periods	O
of	O
time	O
.	O
</s>
<s>
Accell/SQL	O
(	O
4GL	B-Language
)	O
from	O
Unify	O
Corporation	O
.	O
</s>
<s>
Extract	O
data	O
from	O
files	O
or	O
database	O
to	O
create	O
reports	O
in	O
a	O
wide	O
range	O
of	O
formats	O
is	O
done	O
by	O
the	O
report	B-General_Concept
generator	I-General_Concept
tools	O
.	O
</s>
