<s>
Umlaut	B-Library
is	O
an	O
open	B-Application
source	I-Application
front-end	O
for	O
a	O
link	O
resolver	O
for	O
libraries	O
,	O
which	O
deals	O
with	O
advertising	O
services	O
for	O
specific	O
known	O
citations	O
.	O
</s>
<s>
It	O
runs	O
as	O
Ruby	B-Application
on	I-Application
Rails	I-Application
application	O
via	O
an	O
engine	B-Application
gem	I-Application
.	O
</s>
<s>
Umlaut	B-Library
accepts	O
requests	O
in	O
OpenURL	O
format	O
,	O
but	O
has	O
no	O
knowledge	O
base	O
of	O
its	O
own	O
,	O
and	O
is	O
intended	O
to	O
be	O
used	O
as	O
a	O
front-end	O
for	O
an	O
existing	O
knowledge	O
base	O
.	O
</s>
<s>
Currently	O
only	O
SFX	B-Application
is	O
supported	O
(	O
using	O
the	O
SFX	B-Application
API	O
)	O
,	O
but	O
other	O
plugins	O
can	O
be	O
written	O
.	O
</s>
<s>
Umlaut	B-Library
accepts	O
an	O
OpenURL	O
query	O
and	O
the	O
user	O
's	O
IP	B-Protocol
address	I-Protocol
,	O
and	O
determines	O
if	O
there	O
are	O
available	O
link	O
resolvers	O
for	O
that	O
address	O
.	O
</s>
<s>
Umlaut	B-Library
then	O
tries	O
to	O
enrich	O
the	O
item	O
metadata	O
by	O
querying	O
additional	O
sources	O
of	O
information	O
depending	O
on	O
what	O
the	O
original	O
request	O
includes	O
.	O
</s>
