<s>
Harbour	B-Application
is	O
a	O
computer	O
programming	O
language	O
,	O
primarily	O
used	O
to	O
create	O
database/business	O
programs	O
.	O
</s>
<s>
It	O
is	O
a	O
modernized	O
,	O
open	O
sourced	O
and	O
cross-platform	B-Operating_System
version	O
of	O
the	O
older	O
Clipper	B-Application
system	O
,	O
which	O
in	O
turn	O
developed	O
from	O
the	O
dBase	B-Application
database	O
market	O
of	O
the	O
1980s	O
and	O
1990s	O
.	O
</s>
<s>
Harbour	B-Application
code	O
using	O
the	O
same	O
databases	O
can	O
be	O
compiled	O
under	O
a	O
wide	O
variety	O
of	O
platforms	O
,	O
including	O
Microsoft	B-Application
Windows	I-Application
,	O
Linux	B-Application
,	O
Unix	B-Application
variants	O
,	O
several	O
BSD	B-Operating_System
descendants	O
,	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
,	O
MINIX	B-Application
3	I-Application
,	O
Windows	B-Operating_System
CE	I-Operating_System
,	O
Pocket	B-Device
PC	I-Device
,	O
Symbian	B-Operating_System
,	O
iOS	B-Application
,	O
Android	B-Application
,	O
QNX	B-Operating_System
,	O
VxWorks	B-Operating_System
,	O
OS/2	B-Application
(	O
including	O
eComStation	B-Device
and	O
ArcaOS	B-Device
)	O
,	O
BeOS/Haiku	O
,	O
</s>
<s>
AIX	B-Application
and	O
MS-DOS	B-Application
.	O
</s>
<s>
The	O
idea	O
of	O
a	O
free	O
software	O
Clipper	B-Application
compiler	O
had	O
been	O
floating	O
around	O
for	O
a	O
long	O
time	O
and	O
the	O
subject	O
has	O
often	O
cropped	O
up	O
in	O
discussion	O
on	O
comp.lang.clipper	O
.	O
</s>
<s>
Antonio	O
Linares	O
founded	O
the	O
Harbour	B-Application
project	O
and	O
the	O
implementation	O
was	O
started	O
in	O
March	O
1999	O
.	O
</s>
<s>
The	O
name	O
"	O
Harbour	B-Application
"	O
was	O
proposed	O
by	O
Linares	O
,	O
it	O
is	O
a	O
play	O
on	O
a	O
Clipper	B-Application
as	O
a	O
type	O
of	O
ship	O
.	O
</s>
<s>
Harbour	B-Application
is	O
a	O
synonym	O
for	O
port	O
(	O
where	O
ships	O
dock	O
)	O
,	O
and	O
Harbour	B-Application
is	O
a	O
port	O
of	O
the	O
Clipper	B-Application
language	O
.	O
</s>
<s>
In	O
2009	O
Harbour	B-Application
was	O
substantially	O
redesigned	O
,	O
mainly	O
by	O
Viktor	O
Szakáts	O
and	O
Przemyslaw	O
Czerpak	O
.	O
</s>
<s>
Harbour	B-Application
extends	O
the	O
Clipper	B-Application
Replaceable	O
Database	B-Application
Drivers	I-Application
(	O
RDD	O
)	O
approach	O
.	O
</s>
<s>
It	O
offers	O
multiple	O
RDDs	O
such	O
as	O
DBF	B-Application
,	O
DBFNTX	O
,	O
DBFCDX	O
,	O
DBFDBT	O
and	O
DBFFPT	O
.	O
</s>
<s>
In	O
Harbour	B-Application
multiple	O
RDDs	O
can	O
be	O
used	O
in	O
a	O
single	O
application	O
,	O
and	O
new	O
logical	O
RDDs	O
can	O
be	O
defined	O
by	O
combining	O
other	O
RDDs	O
.	O
</s>
<s>
Third-party	O
RDDs	O
,	O
like	O
RDDSQL	O
,	O
RDDSIX	O
,	O
RMDBFCDX	O
,	O
Advantage	B-Application
Database	I-Application
Server	I-Application
,	O
and	O
Mediator	O
exemplify	O
some	O
of	O
the	O
RDD	O
architecture	O
features	O
.	O
</s>
<s>
NETIO	O
and	O
LetoDB	O
provide	O
remote	O
access	O
over	O
TCP	B-Protocol
protocol	I-Protocol
.	O
</s>
<s>
Harbour	B-Application
also	O
offers	O
ODBC	B-Application
support	O
by	O
means	O
of	O
an	O
OOP	B-Language
syntax	O
,	O
and	O
ADO	B-Library
support	O
by	O
means	O
of	O
OLE	B-Application
.	O
</s>
<s>
MySQL	B-Application
,	O
PostgreSQL	B-Application
,	O
SQLite	B-Language
,	O
Firebird	B-Application
,	O
Oracle	B-General_Concept
are	O
examples	O
of	O
databases	O
which	O
Harbour	B-Application
can	O
connect	O
to	O
.	O
</s>
<s>
xBase	B-Language
technologies	O
often	O
are	O
confused	O
with	O
RDBMS	O
software	O
.	O
</s>
<s>
Although	O
this	O
is	O
true	O
,	O
xBase	B-Language
is	O
more	O
than	O
a	O
simple	O
database	O
system	O
as	O
at	O
the	O
same	O
time	O
xBase	B-Language
languages	O
using	O
purely	O
DBF	B-Application
can	O
not	O
provide	O
the	O
full	O
concept	O
of	O
a	O
real	O
RDBMS	O
.	O
</s>
<s>
Unlike	O
Java	B-Language
which	O
is	O
intended	O
to	O
be	O
written	O
once	O
,	O
run	O
anywhere	O
,	O
Harbour	B-Application
aims	O
to	O
be	O
written	O
once	O
,	O
compiled	O
anywhere	O
.	O
</s>
<s>
As	O
the	O
same	O
compiler	O
is	O
available	O
for	O
all	O
of	O
the	O
above	O
operating	B-General_Concept
systems	I-General_Concept
,	O
there	O
is	O
no	O
need	O
for	O
recoding	O
to	O
produce	O
identical	O
products	O
for	O
different	O
platforms	O
,	O
except	O
when	O
operating	B-General_Concept
system	I-General_Concept
dependent	O
features	O
are	O
used	O
.	O
</s>
<s>
Cross-compiling	O
is	O
supported	O
with	O
MinGW	B-Application
.	O
</s>
<s>
Under	O
Microsoft	B-Application
Windows	I-Application
,	O
Harbour	B-Application
is	O
more	O
stable	O
but	O
less	O
well-documented	O
than	O
Clipper	B-Application
,	O
but	O
has	O
multi-platform	B-Operating_System
capability	O
and	O
is	O
more	O
transparent	O
,	O
customizable	O
and	O
can	O
run	O
from	O
a	O
USB	O
flash	O
drive	O
.	O
</s>
<s>
Under	O
Linux	B-Application
and	O
Windows	O
Mobile	O
,	O
Clipper	B-Application
source	O
code	O
can	O
be	O
compiled	O
with	O
Harbour	B-Application
with	O
very	O
little	O
adaptation	O
.	O
</s>
<s>
Most	O
software	O
originally	O
written	O
to	O
run	O
on	O
Xbase++	B-Language
,	O
FlagShip	O
,	O
FoxPro	O
,	O
xHarbour	B-Language
and	O
others	O
dialects	O
can	O
be	O
compiled	O
with	O
Harbor	O
with	O
some	O
adaptation	O
.	O
</s>
<s>
As	O
of	O
2010	O
many	O
efforts	O
have	O
been	O
made	O
to	O
make	B-Application
the	O
transition	O
from	O
other	O
xBase	B-Language
dialects	O
easier	O
.	O
</s>
<s>
Harbour	B-Application
can	O
use	O
the	O
following	O
C	B-Language
compilers	O
,	O
among	O
others	O
:	O
</s>
<s>
GCC	B-Application
,	O
</s>
<s>
MinGW	B-Application
,	O
</s>
<s>
Clang	B-Application
,	O
</s>
<s>
ICC	B-Language
,	O
</s>
<s>
Microsoft	B-Application
Visual	I-Application
C++	I-Application
(	O
6.0	O
+	O
)	O
,	O
</s>
<s>
Borland	B-Application
C++	I-Application
,	O
</s>
<s>
Watcom	B-Application
C	I-Application
,	O
</s>
<s>
Sun	B-Application
Studio	I-Application
.	O
</s>
<s>
Harbour	B-Application
can	O
make	B-Application
use	O
of	O
multiple	O
Graphical	O
Terminal	O
emulation	O
,	O
including	O
console	O
drivers	O
,	O
and	O
Hybrid	O
Console/GUIs	O
,	O
such	O
as	O
GTWvt	O
,	O
and	O
GTWvg	O
.	O
</s>
<s>
Harbour	B-Application
supports	O
external	O
GUI	B-Application
's	O
,	O
free	O
(	O
e.g.	O
</s>
<s>
HBQt	O
,	O
HWGui	O
,	O
Mini-GUI	O
(	O
latest	O
version	O
based	O
on	O
Qt	O
and	O
QtContribs	O
)	O
and	O
commercial	O
(	O
e.g.	O
</s>
<s>
Harbour	B-Application
is	O
100%	O
Clipper-compatible	O
and	O
supports	O
many	O
language	O
syntax	O
extensions	O
including	O
greatly	O
extended	O
run-time	O
libraries	O
such	O
as	O
OLE	B-Application
,	O
Blat	O
,	O
OpenSSL	B-Language
,	O
Free	O
Image	O
,	O
GD	B-Language
,	O
hbtip	O
,	O
hbtpathy	O
,	O
PCRE	B-Language
,	O
hbmzip	O
(	O
zlib	B-Language
)	O
,	O
hbbz2	O
(	O
bzip2	B-Application
)	O
,	O
cURL	B-Language
,	O
Cairo	B-Language
,	O
its	O
own	O
implementation	O
of	O
CA-Tools	O
,	O
updated	O
NanFor	O
libraries	O
and	O
many	O
others	O
.	O
</s>
<s>
Harbour	B-Application
has	O
an	O
active	O
development	O
community	O
and	O
extensive	O
third	O
party	O
support	O
.	O
</s>
<s>
Any	O
xBase	B-Language
language	O
provides	O
a	O
very	O
productive	O
way	O
to	O
build	O
business	O
and	O
data	O
intensive	O
applications	O
.	O
</s>
<s>
Harbour	B-Application
is	O
not	O
an	O
exception	O
.	O
</s>
<s>
One	O
of	O
the	O
most	O
powerful	O
features	O
of	O
xBase	B-Language
languages	O
is	O
the	O
Macro	O
Operator	O
'	O
&	O
 '	O
.	O
</s>
<s>
Harbour	B-Application
's	O
implementation	O
of	O
the	O
Macro	O
Operator	O
allows	O
for	O
runtime	O
compilation	O
of	O
any	O
valid	O
Harbour	B-Application
expression	O
.	O
</s>
<s>
In	O
other	O
words	O
,	O
any	O
Harbour	B-Application
application	O
may	O
be	O
extended	O
and	O
modified	O
at	O
runtime	O
to	O
compile	O
and	O
execute	O
additional	O
code	O
on-demand	O
.	O
</s>
<s>
The	O
latest	O
Macro	O
compiler	O
can	O
compile	O
any	O
valid	O
Harbour	B-Application
code	O
including	O
code	O
to	O
per-process	O
before	O
compile	O
.	O
</s>
<s>
Programming	O
in	O
an	O
OOP	B-Language
style	O
is	O
a	O
broader	O
issue	O
than	O
a	O
specific	O
library	O
or	O
a	O
specific	O
interface	O
,	O
but	O
OOP	B-Language
programming	O
is	O
something	O
many	O
Clipper	B-Application
programmers	O
have	O
come	O
to	O
expect	O
.	O
</s>
<s>
CA-Clipper	B-Application
5.2	O
and	O
especially	O
5.3	O
added	O
a	O
number	O
of	O
base	O
classes	O
,	O
and	O
a	O
matching	O
OOP	B-Language
syntax	O
.	O
</s>
<s>
Libraries	O
such	O
as	O
,	O
FieWin	O
,	O
Clip4Win	O
,	O
and	O
Top	O
Class	O
provide	O
additional	O
OOP	B-Language
functionality	O
.	O
</s>
<s>
Harbour	B-Application
has	O
OOP	B-Language
extensions	O
with	O
full	O
support	O
for	O
classes	O
including	O
inheritance	O
,	O
based	O
on	O
Class(y )	O
syntax	O
.	O
</s>
<s>
OOP	B-Language
syntax	O
in	O
Harbour	B-Application
is	O
very	O
similar	O
to	O
that	O
of	O
earlier	O
Clipper	B-Application
class	O
libraries	O
so	O
it	O
should	O
be	O
possible	O
to	O
maintain	O
legacy	O
Clipper	B-Application
code	O
with	O
minimal	O
changes	O
.	O
</s>
<s>
Harbour	B-Application
as	O
every	O
xBase	B-Language
language	O
is	O
case	O
insensitive	O
and	O
can	O
optionally	O
accept	O
keywords	O
written	O
just	O
by	O
their	O
first	O
four	O
characters	O
.	O
</s>
<s>
Harbour	B-Application
has	O
six	O
scalar	O
types	O
:	O
Nil	O
,	O
String	O
,	O
Date	O
,	O
Logical	O
,	O
Numeric	O
,	O
Pointer	O
,	O
and	O
four	O
complex	O
types	O
:	O
Array	O
,	O
Object	O
,	O
CodeBlock	B-Language
,	O
and	O
Hash	B-Algorithm
.	O
</s>
<s>
Hashes	O
,	O
or	O
associative	B-Application
arrays	I-Application
,	O
are	O
unordered	O
collections	O
of	O
any	O
type	O
values	O
indexed	O
by	O
their	O
associated	O
key	O
,	O
which	O
may	O
be	O
of	O
any	O
scalar	O
or	O
complex	O
type	O
.	O
</s>
<s>
CodeBlock	B-Language
:	O
</s>
<s>
Hash	B-Algorithm
:	O
</s>
<s>
Such	O
Codeblocks	O
may	O
be	O
returned	O
as	O
a	O
value	O
,	O
or	O
by	O
means	O
of	O
an	O
argument	O
passed	O
,	O
in	O
such	O
case	O
the	O
Codeblock	B-Language
will	O
"	O
outlive	O
"	O
the	O
routine	O
in	O
which	O
it	O
was	O
defined	O
,	O
and	O
any	O
variables	O
it	O
references	O
,	O
will	O
be	O
a	O
variable	O
.	O
</s>
<s>
Detached	O
variables	O
will	O
maintain	O
their	O
value	O
for	O
as	O
long	O
as	O
a	O
Codeblock	B-Language
referencing	O
them	O
still	O
exists	O
.	O
</s>
<s>
Such	O
values	O
will	O
be	O
shared	O
with	O
any	O
other	O
Codeblock	B-Language
which	O
may	O
have	O
access	O
to	O
those	O
same	O
variables	O
.	O
</s>
<s>
If	O
the	O
Codeblock	B-Language
did	O
not	O
outlive	O
its	O
containing	O
routine	O
,	O
and	O
will	O
be	O
evaluated	O
within	O
the	O
lifetime	O
of	O
the	O
routine	O
in	O
which	O
it	O
is	O
defined	O
,	O
changes	O
to	O
its	O
Detached	O
Variables(s )	O
by	O
means	O
of	O
its	O
evaluation	O
,	O
will	O
be	O
reflected	O
back	O
at	O
its	O
parent	O
routine	O
.	O
</s>
<s>
and	O
are	O
resolved	O
at	O
compile	O
time	O
,	O
and	O
thus	O
are	O
much	O
faster	O
than	O
and	O
variables	O
which	O
are	O
dynamic	O
entities	O
accessed	O
by	O
means	O
of	O
a	O
runtime	O
Symbol	B-Application
table	I-Application
.	O
</s>
<s>
The	O
basic	O
control	O
structures	O
include	O
all	O
of	O
the	O
standard	O
dBase	B-Application
,	O
and	O
Clipper	B-Application
control	O
structures	O
as	O
well	O
as	O
additional	O
ones	O
inspired	O
by	O
the	O
C	B-Language
or	O
Java	B-Language
programming	I-Language
languages	I-Language
:	O
</s>
<s>
The	O
...	O
is	O
a	O
sequence	O
of	O
one	O
or	O
more	O
Harbour	B-Application
statements	O
,	O
and	O
square	O
brackets	O
 [  ] 	O
denote	O
optional	O
syntax	O
.	O
</s>
<s>
The	O
collection	O
expression	O
may	O
be	O
an	O
Array	O
(	O
of	O
any	O
type	O
or	O
combinations	O
of	O
types	O
)	O
,	O
a	O
Hash	B-Algorithm
Table	I-Algorithm
,	O
or	O
an	O
Object	O
type	O
.	O
</s>
<s>
Harbour	B-Application
supports	O
a	O
SWITCH	O
construct	O
inspired	O
by	O
the	O
C	B-Language
implementation	O
of	O
switch( )	O
.	O
</s>
<s>
The	O
EXIT	O
optional	O
statement	O
is	O
the	O
equivalent	O
of	O
the	O
C	B-Language
statement	O
break	O
,	O
and	O
if	O
present	O
,	O
execution	O
of	O
the	O
SWITCH	O
structure	O
will	O
end	O
when	O
the	O
EXIT	O
statement	O
is	O
reached	O
,	O
otherwise	O
it	O
will	O
continue	O
with	O
the	O
first	O
statement	O
below	O
the	O
next	O
CASE	O
statement	O
(	O
fall	O
through	O
)	O
.	O
</s>
<s>
Additionally	O
the	O
Harbour	B-Application
Error	O
Object	O
supports	O
canDefault	O
,	O
canRetry	O
and	O
canSubstitute	O
properties	O
,	O
which	O
allows	O
error	O
handlers	O
to	O
perform	O
some	O
preparations	O
,	O
and	O
then	O
request	O
a	O
Retry	O
Operation	O
,	O
a	O
Resume	O
,	O
or	O
return	O
a	O
Value	O
to	O
replace	O
the	O
expression	O
triggering	O
the	O
error	O
condition	O
.	O
</s>
<s>
Procedures	O
and	O
Functions	O
in	O
Harbour	B-Application
can	O
be	O
specified	O
with	O
the	O
keywords	O
PROCEDURE	O
,	O
or	O
FUNCTION	O
.	O
</s>
<s>
hbrun	O
–	O
Shell	O
interpreter	O
for	O
Harbour	B-Application
.	O
</s>
<s>
All	O
tools	O
are	O
multi-platform	B-Operating_System
.	O
</s>
<s>
Today	O
Harbour	B-Application
development	O
is	O
led	O
by	O
Viktor	O
Szakáts	O
in	O
collaboration	O
with	O
Przemysław	O
Czerpak	O
who	O
also	O
contributes	O
many	O
components	O
of	O
the	O
core	O
language	O
and	O
supplementary	O
components	O
.	O
</s>
<s>
Other	O
members	O
of	O
the	O
development	O
community	O
send	O
changes	O
to	O
the	O
GitHub	B-Application
source	O
repository	O
.	O
</s>
<s>
As	O
of	O
2015	O
Harbour	B-Application
development	O
is	O
active	O
and	O
vibrant	O
.	O
</s>
<s>
xHarbour	B-Language
is	O
a	O
fork	B-Application
of	O
the	O
earlier	O
Harbour	B-Application
project	O
.	O
</s>
<s>
xHarbour	B-Language
takes	O
a	O
more	O
aggressive	O
approach	O
to	O
implementing	O
new	O
features	O
in	O
the	O
language	O
,	O
while	O
Harbour	B-Application
is	O
more	O
conservative	O
in	O
its	O
approach	O
,	O
aiming	O
first	O
of	O
all	O
for	O
an	O
exact	O
replication	O
of	O
Clipper	B-Application
behaviour	O
and	O
then	O
implementing	O
new	O
features	O
and	O
extensions	O
as	O
a	O
secondary	O
consideration	O
.	O
</s>
<s>
It	O
should	O
also	O
be	O
noted	O
that	O
Harbour	B-Application
is	O
supported	O
on	O
a	O
wide	O
variety	O
of	O
operating	B-General_Concept
systems	I-General_Concept
while	O
xHarbour	B-Language
only	O
really	O
supports	O
MS	B-Application
Windows	I-Application
and	O
Linux	B-Application
32-bit	O
.	O
</s>
<s>
The	O
Harbour	B-Application
developers	O
have	O
attempted	O
to	O
document	O
all	O
hidden	O
behaviour	O
in	O
the	O
Clipper	B-Application
language	O
and	O
test	O
Harbour-compiled	O
code	O
alongside	O
the	O
same	O
code	O
compiled	O
with	O
Clipper	B-Application
to	O
maintain	O
compatibility	O
.	O
</s>
<s>
The	O
Harbour	B-Application
developers	O
explicitly	O
reject	O
extensions	O
to	O
the	O
language	O
where	O
those	O
extensions	O
would	O
break	O
Clipper	B-Application
compatibility	O
.	O
</s>
<s>
These	O
rejections	O
were	O
softened	O
recently	O
since	O
the	O
new	O
Harbour	B-Application
architecture	O
allows	O
extensions	O
out	O
of	O
the	O
core	O
compiler	O
.	O
</s>
<s>
A	O
detailed	O
comparison	O
between	O
extensions	O
implemented	O
in	O
Harbour	B-Application
and	O
xHarbour	B-Language
can	O
be	O
found	O
in	O
the	O
source	O
repository	O
of	O
the	O
project	O
on	O
GitHub	B-Application
.	O
</s>
<s>
Marinas-GUI	O
–	O
Multi-Platform	B-Operating_System
QT	O
Based	O
GUI	B-Application
Development	O
Package	O
for	O
Harbour	B-Application
.	O
</s>
<s>
Marinas-GUI	O
downloads	O
as	O
a	O
complete	O
installation	O
package	O
for	O
the	O
chosen	O
target	O
platform	O
(	O
IDE	O
,	O
Version	O
Control	O
,	O
Harbour/C	O
Compiler	O
,	O
Libraries	O
etc	O
.	O
)	O
</s>
