<s>
Microsoft	B-Language
QuickBASIC	I-Language
(	O
also	O
QB	O
)	O
is	O
an	O
Integrated	B-Application
Development	I-Application
Environment	I-Application
(	O
or	O
IDE	O
)	O
and	O
compiler	B-Language
for	O
the	O
BASIC	O
programming	O
language	O
that	O
was	O
developed	O
by	O
Microsoft	O
.	O
</s>
<s>
QuickBASIC	B-Language
runs	O
mainly	O
on	O
DOS	B-Device
,	O
though	O
there	O
was	O
also	O
a	O
short-lived	O
version	O
for	O
the	O
classic	B-Application
Mac	I-Application
OS	I-Application
.	O
</s>
<s>
It	O
is	O
loosely	O
based	O
on	O
GW-BASIC	B-Language
but	O
adds	O
user-defined	O
types	O
,	O
improved	O
programming	O
structures	O
,	O
better	O
graphics	O
and	O
disk	O
support	O
and	O
a	O
compiler	B-Language
in	O
addition	O
to	O
the	O
interpreter	B-Language
.	O
</s>
<s>
Microsoft	O
marketed	O
QuickBASIC	B-Language
as	O
the	O
introductory	O
level	O
for	O
their	O
BASIC	O
Professional	O
Development	O
System	O
.	O
</s>
<s>
Microsoft	O
marketed	O
two	O
other	O
similar	O
IDEs	O
for	O
C	O
and	O
Pascal	O
,	O
viz	O
QuickC	B-Application
and	O
QuickPascal	B-Language
.	O
</s>
<s>
Microsoft	O
released	O
the	O
first	O
version	O
of	O
QuickBASIC	B-Language
on	O
August	O
18	O
,	O
1985	O
on	O
a	O
single	O
5.25-inch	O
360KB	O
floppy	B-Device
disk	I-Device
.	O
</s>
<s>
QuickBASIC	B-Language
version	O
2.0	O
and	O
later	O
contained	O
an	O
Integrated	B-Application
Development	I-Application
Environment	I-Application
(	O
IDE	O
)	O
,	O
allowing	O
users	O
to	O
edit	O
directly	O
in	O
its	O
on-screen	O
text	O
editor	O
.	O
</s>
<s>
Although	O
still	O
supported	O
in	O
QuickBASIC	B-Language
,	O
line	O
numbers	O
became	O
optional	O
.	O
</s>
<s>
Later	O
versions	O
also	O
added	O
control	O
structures	O
,	O
such	O
as	O
multiline	O
conditional	B-Language
statements	I-Language
and	O
loop	O
blocks	O
.	O
</s>
<s>
Microsoft	O
's	O
"	O
PC	O
BASIC	O
Compiler	B-Language
"	O
was	O
included	O
for	O
compiling	B-Language
programs	O
into	O
DOS	B-Device
executables	O
.	O
</s>
<s>
Beginning	O
with	O
version	O
4.0	O
,	O
the	O
editor	O
included	O
an	O
interpreter	B-Language
that	O
allowed	O
the	O
programmer	O
to	O
run	O
the	O
program	O
without	O
leaving	O
the	O
editor	O
.	O
</s>
<s>
The	O
interpreter	B-Language
was	O
used	O
to	O
debug	O
a	O
program	O
before	O
creating	O
an	O
executable	O
file	O
.	O
</s>
<s>
Unfortunately	O
,	O
there	O
were	O
some	O
subtle	O
differences	O
between	O
the	O
interpreter	B-Language
and	O
the	O
compiler	B-Language
,	O
which	O
meant	O
that	O
large	O
programs	O
that	O
ran	O
correctly	O
in	O
the	O
interpreter	B-Language
might	O
fail	O
after	O
compilation	B-Language
,	O
or	O
not	O
compile	B-Language
at	O
all	O
because	O
of	O
differences	O
in	O
the	O
memory	O
management	O
routines	O
.	O
</s>
<s>
The	O
last	O
version	O
of	O
QuickBASIC	B-Language
was	O
version	O
4.5	O
(	O
1988	O
)	O
,	O
although	O
development	O
of	O
the	O
Microsoft	B-Language
BASIC	I-Language
Professional	I-Language
Development	I-Language
System	I-Language
(	O
PDS	O
)	O
continued	O
until	O
its	O
last	O
release	O
of	O
version	O
7.1	O
in	O
October	O
1990	O
.	O
</s>
<s>
At	O
the	O
same	O
time	O
,	O
the	O
QuickBASIC	B-Language
packaging	O
was	O
silently	O
changed	O
so	O
that	O
the	O
disks	O
used	O
the	O
same	O
compression	O
used	O
for	O
BASIC	O
PDS	O
7.1	O
.	O
</s>
<s>
The	O
Basic	O
PDS	O
7.x	O
version	O
of	O
the	O
IDE	O
was	O
called	O
QuickBASIC	B-Language
Extended	O
(	O
QBX	O
)	O
,	O
and	O
it	O
only	O
ran	O
on	O
DOS	B-Device
,	O
unlike	O
the	O
rest	O
of	O
Basic	O
PDS	O
7.x	O
,	O
which	O
also	O
ran	O
on	O
OS/2	O
.	O
</s>
<s>
The	O
successor	O
to	O
QuickBASIC	B-Language
and	O
Basic	O
PDS	O
was	O
Visual	B-Language
Basic	I-Language
version	O
1.0	O
for	O
MS-DOS	B-Application
,	O
shipped	O
in	O
Standard	O
and	O
Professional	O
versions	O
.	O
</s>
<s>
Later	O
versions	O
of	O
Visual	B-Language
Basic	I-Language
did	O
not	O
include	O
DOS	B-Device
versions	O
,	O
as	O
Microsoft	O
concentrated	O
on	O
Windows	B-Application
applications	I-Application
.	O
</s>
<s>
A	O
subset	O
of	O
QuickBASIC	B-Language
4.5	O
,	O
named	O
QBasic	B-Language
,	O
was	O
included	O
with	O
MS-DOS	B-Application
5	O
and	O
later	O
versions	O
,	O
replacing	O
the	O
GW-BASIC	B-Language
included	O
with	O
previous	O
versions	O
of	O
MS-DOS	B-Application
.	O
</s>
<s>
Compared	O
to	O
QuickBASIC	B-Language
,	O
QBasic	B-Language
is	O
limited	O
to	O
an	O
interpreter	B-Language
only	O
,	O
lacks	O
a	O
few	O
functions	O
,	O
can	O
only	O
handle	O
programs	O
of	O
a	O
limited	O
size	O
,	O
and	O
lacks	O
support	O
for	O
separate	O
program	O
modules	O
.	O
</s>
<s>
Since	O
it	O
lacks	O
a	O
compiler	B-Language
,	O
it	O
cannot	O
be	O
used	O
to	O
produce	O
executable	O
files	O
,	O
although	O
its	O
program	O
source	O
code	O
can	O
still	O
be	O
compiled	B-Language
by	O
a	O
QuickBASIC	B-Language
4.5	O
,	O
PDS	O
7.x	O
or	O
VBDOS	B-Language
1.0	I-Language
compiler	B-Language
,	O
if	O
available	O
.	O
</s>
<s>
QuickBASIC	B-Language
1.00	O
for	O
the	O
Apple	B-Device
Macintosh	I-Device
operating	O
system	O
was	O
launched	O
in	O
1988	O
.	O
</s>
<s>
It	O
was	O
officially	O
supported	O
on	O
machines	O
running	O
System	B-Protocol
6	I-Protocol
with	O
at	O
least	O
1MB	O
of	O
RAM	O
.	O
</s>
<s>
QuickBASIC	B-Language
could	O
also	O
be	O
run	O
on	O
System	B-Operating_System
7	I-Operating_System
,	O
as	O
long	O
as	O
32-bit	O
addressing	O
was	O
disabled	O
.	O
</s>
<s>
Bubble	B-Algorithm
sort	I-Algorithm
:	O
</s>
<s>
QuickBASIC	B-Language
has	O
an	O
unofficial	O
community	O
of	O
hobby	O
programmers	O
who	O
use	O
the	O
compiler	B-Language
to	O
write	O
video	O
games	O
,	O
GUIs	B-Application
and	O
utilities	B-Application
.	O
</s>
<s>
The	O
community	O
has	O
dedicated	O
several	O
Web	O
sites	O
,	O
message	B-Application
boards	I-Application
and	O
online	O
magazines	O
to	O
the	O
language	O
.	O
</s>
<s>
Today	O
,	O
programmers	O
sometimes	O
use	O
DOS	B-Device
emulators	B-Application
,	O
such	O
as	O
DOSBox	B-Application
,	O
to	O
run	O
QuickBASIC	B-Language
on	O
Linux	B-Application
and	O
on	O
modern	O
personal	B-Architecture
computer	I-Architecture
hardware	I-Architecture
that	O
no	O
longer	O
supports	O
the	O
compiler	B-Language
.	O
</s>
<s>
Alternatives	O
to	O
this	O
include	O
FreeBASIC	B-Language
and	O
QB64	B-Application
,	O
but	O
they	O
cannot	O
yet	O
run	O
all	O
QBasic/QuickBASIC	O
programs	O
.	O
</s>
<s>
Since	O
2008	O
,	O
a	O
set	O
of	O
TCP/IP	B-Protocol
routines	O
for	O
QuickBASIC	B-Language
4.x	O
and	O
7.1	O
has	O
revitalized	O
some	O
interest	O
in	O
the	O
software	O
.	O
</s>
<s>
In	O
particular	O
,	O
the	O
vintage	O
computer	O
hobbyist	O
community	O
has	O
been	O
able	O
to	O
write	O
software	O
for	O
old	O
computers	O
that	O
run	O
DOS	B-Device
,	O
allowing	O
these	O
machines	O
to	O
access	O
other	O
computers	O
through	O
a	O
LAN	B-General_Concept
or	O
the	O
internet	O
.	O
</s>
<s>
This	O
has	O
allowed	O
systems	O
even	O
as	O
old	O
as	O
an	O
8088	B-Device
to	O
serve	O
new	O
functions	O
,	O
such	O
as	O
acting	O
as	O
a	O
Web	B-Application
server	I-Application
or	O
using	O
IRC	B-Protocol
.	O
</s>
<s>
Microsoft	O
's	O
Visual	B-Language
Basic	I-Language
was	O
the	O
successor	O
of	O
QuickBASIC	B-Language
.	O
</s>
<s>
Other	O
compilers	B-Language
,	O
like	O
PowerBASIC	B-Language
and	O
FreeBASIC	B-Language
,	O
have	O
varying	O
degrees	O
of	O
compatibility	O
.	O
</s>
<s>
QB64	B-Application
,	O
a	O
multiplatform	B-Operating_System
QuickBASIC	B-Language
to	O
C++	O
translator	O
,	O
retains	O
close	O
to	O
100%	O
compatibility	O
and	O
compiles	B-Language
natively	O
for	O
Windows	B-Application
,	O
Linux	B-Application
and	O
macOS	B-Application
.	O
</s>
