<s>
Elvin	B-Application
is	O
an	O
event	O
routing	O
service	O
using	O
a	O
publish/subscribe	B-Operating_System
event	O
delivery	O
model	O
.	O
</s>
<s>
Elvin	B-Application
is	O
most	O
distinguished	O
from	O
other	O
such	O
systems	O
by	O
its	O
support	O
of	O
a	O
sophisticated	O
content-based	O
subscription	O
system	O
.	O
</s>
<s>
Elvin	B-Application
clients	O
subscribe	O
to	O
events	O
using	O
a	O
language	O
that	O
resembles	O
C	B-Language
boolean	O
expressions	O
.	O
</s>
<s>
The	O
Elvin	B-Application
subscription	O
language	O
supports	O
a	O
range	O
of	O
operations	O
for	O
matching	O
numeric	O
and	O
string	O
values	O
,	O
including	O
the	O
use	O
of	O
regular	B-Language
expression	I-Language
matching	O
.	O
</s>
<s>
Elvin	B-Application
is	O
oriented	O
around	O
providing	O
a	O
fast	O
,	O
flexible	O
event	O
service	O
that	O
can	O
be	O
federated	O
to	O
form	O
wide-area	O
event	O
notification	O
networks	O
.	O
</s>
<s>
In	O
order	O
to	O
achieve	O
these	O
goals	O
it	O
does	O
not	O
provide	O
persistence	O
,	O
durability	B-General_Concept
or	O
guaranteed	O
delivery	O
.	O
</s>
<s>
Elvin	B-Application
can	O
thought	O
of	O
as	O
providing	O
a	O
middle	O
ground	O
between	O
low-level	O
network	O
multicast	O
and	O
higher-level	O
,	O
more	O
complex	O
,	O
event	O
brokers	O
such	O
as	O
JMS	B-Language
.	O
</s>
<s>
In	O
2003	O
,	O
the	O
research	O
group	O
that	O
created	O
Elvin	B-Application
left	O
DSTC	O
to	O
found	O
Mantara	O
software	O
in	O
order	O
to	O
develop	O
commercial	O
applications	O
of	O
Elvin	B-Application
.	O
</s>
<s>
In	O
November	O
2006	O
,	O
Mantara	O
announced	O
that	O
it	O
would	O
be	O
ceasing	O
to	O
support	O
Elvin	B-Application
as	O
a	O
standalone	O
commercial	O
product	O
by	O
the	O
end	O
of	O
2007	O
.	O
</s>
<s>
The	O
specifications	O
for	O
the	O
Elvin	B-Application
protocols	O
have	O
been	O
made	O
available	O
,	O
and	O
a	O
new	O
implementation	O
of	O
Elvin	B-Application
has	O
subsequently	O
been	O
developed	O
,	O
Avis	O
,	O
an	O
open-source	O
(	O
GPL	B-License
)	O
implementation	O
.	O
</s>
