<s>
In	O
the	O
field	O
of	O
VoIP	B-Application
networking	O
,	O
the	O
Open	B-Protocol
Phone	I-Protocol
Abstraction	I-Protocol
Library	I-Protocol
(	O
OPAL	O
)	O
continues	O
the	O
open-source	B-License
openh323	B-Protocol
project	O
to	O
support	O
a	O
wide	O
range	O
of	O
commonly	O
used	O
protocols	O
used	O
to	O
send	O
voice	O
,	O
video	O
and	O
fax	O
data	O
over	O
IP	O
networks	O
rather	O
than	O
being	O
tied	O
to	O
the	O
H.323	B-Protocol
protocol	I-Protocol
.	O
</s>
<s>
Initially	O
,	O
from	O
2007	O
,	O
OPAL	O
supported	O
the	O
H.323	B-Protocol
and	O
Session	B-Application
Initiation	I-Application
Protocol	I-Application
(	O
SIP	O
)	O
protocols	O
,	O
but	O
it	O
has	O
grown	O
to	O
include	O
Asterisk	O
IAX2	B-Protocol
.	O
</s>
<s>
OPAL	O
implements	O
a	O
wide	O
range	O
of	O
Voice	B-Application
over	I-Application
IP	I-Application
(	O
VoIP	B-Application
)	O
protocols	O
for	O
voice	O
,	O
video	O
and	O
fax	O
data	O
over	O
IP	O
networks	O
.	O
</s>
<s>
It	O
is	O
written	O
in	O
C++	O
and	O
released	O
under	O
the	O
Mozilla	B-License
Public	I-License
Licence	I-License
.	O
</s>
<s>
Opal	O
was	O
developed	O
as	O
a	O
derivative	O
of	O
the	O
OpenH323	B-Protocol
library	O
.	O
</s>
<s>
OPAL	O
is	O
used	O
by	O
the	O
open	B-License
source	I-License
Video	O
Conferencing	O
Program	O
Ekiga	B-Language
(	O
formerly	O
GnomeMeeting	B-Language
)	O
.	O
</s>
