<s>
Drools	B-Language
is	O
a	O
business	B-Application
rule	I-Application
management	I-Application
system	I-Application
(	O
BRMS	B-Application
)	O
with	O
a	O
forward	O
and	O
backward	O
chaining	O
inference	O
based	O
rules	O
engine	O
,	O
more	O
correctly	O
known	O
as	O
a	O
production	B-Application
rule	I-Application
system	I-Application
,	O
using	O
an	O
enhanced	O
implementation	O
of	O
the	O
Rete	B-Algorithm
algorithm	I-Algorithm
.	O
</s>
<s>
Drools	B-Language
supports	O
the	O
Java	B-Language
Rules	O
Engine	O
API	O
(	O
Java	B-Language
Specification	O
Request	O
94	O
)	O
standard	O
for	O
its	O
business	O
rule	O
engine	O
and	O
enterprise	O
framework	O
for	O
the	O
construction	O
,	O
maintenance	O
,	O
and	O
enforcement	O
of	O
business	O
policies	O
in	O
an	O
organization	O
,	O
application	O
,	O
or	O
service	O
.	O
</s>
<s>
Red	O
Hat	O
Decision	O
Manager	O
(	O
formerly	O
Red	O
Hat	O
JBoss	B-Language
BRMS	B-Application
)	O
is	O
a	O
business	B-Application
rule	I-Application
management	I-Application
system	I-Application
and	O
reasoning	O
engine	O
for	O
business	O
policy	O
and	O
rules	O
development	O
,	O
access	O
,	O
and	O
change	O
management	O
.	O
</s>
<s>
JBoss	B-Language
Enterprise	O
BRMS	B-Application
is	O
a	O
productized	O
version	O
of	O
Drools	B-Language
with	O
enterprise-level	O
support	O
available	O
.	O
</s>
<s>
JBoss	B-Language
Rules	I-Language
is	O
also	O
a	O
productized	O
version	O
of	O
Drools	B-Language
,	O
but	O
JBoss	B-Language
Enterprise	O
BRMS	B-Application
is	O
the	O
flagship	O
product	O
.	O
</s>
<s>
Business	O
Rules	O
Manager	O
–	O
Drools	B-Language
Guvnor	O
-	O
Guvnor	O
is	O
a	O
centralised	O
repository	O
for	O
Drools	B-Language
Knowledge	O
Bases	O
,	O
with	O
rich	O
web	O
based	O
GUIs	O
,	O
editors	O
,	O
and	O
tools	O
to	O
aid	O
in	O
the	O
management	O
of	O
large	O
numbers	O
of	O
rules	O
.	O
</s>
<s>
Drools	B-Language
and	O
Guvnor	O
are	O
JBoss	B-Language
Community	O
open	O
source	O
projects	O
.	O
</s>
<s>
As	O
they	O
are	O
mature	O
,	O
they	O
are	O
brought	O
into	O
the	O
enterprise-ready	O
product	O
JBoss	B-Language
Enterprise	O
BRMS	B-Application
.	O
</s>
<s>
Components	O
of	O
the	O
JBoss	B-Language
Community	O
version	O
:	O
</s>
<s>
It	O
checks	O
a	O
condition	O
on	O
an	O
instance	O
of	O
the	O
Holiday	O
class	O
,	O
and	O
executes	O
Java	B-Language
code	I-Language
if	O
that	O
condition	O
is	O
true	O
.	O
</s>
<s>
The	O
purpose	O
of	O
dialect	O
"	O
mvel	O
"	O
is	O
to	O
point	O
the	O
getter	O
and	O
setters	O
of	O
the	O
variables	O
of	O
your	O
Plain	B-Language
Old	I-Language
Java	I-Language
Object	I-Language
(	O
POJO	B-Language
)	O
classes	O
.	O
</s>
<s>
Dialect	O
"	O
java	B-Language
"	O
is	O
used	O
to	O
help	O
us	O
write	O
our	O
Java	B-Language
code	I-Language
in	O
our	O
rules	O
.	O
</s>
<s>
We	O
cannot	O
use	O
Java	B-Language
code	I-Language
inside	O
"	O
when	O
"	O
part	O
of	O
the	O
rule	O
but	O
we	O
can	O
use	O
Java	B-Language
code	I-Language
in	O
"	O
then	O
"	O
part	O
.	O
</s>
<s>
The	O
main	O
purpose	O
of	O
putting	O
the	O
$	O
symbol	O
before	O
the	O
variable	O
is	O
to	O
mark	O
the	O
difference	O
between	O
variables	O
of	O
POJO	B-Language
classes	O
and	O
Rules	O
.	O
</s>
