<s>
Blink	B-Application
is	O
a	O
Session	B-Application
Initiation	I-Application
Protocol	I-Application
(	O
SIP	O
)	O
client	B-Protocol
distributed	O
under	O
the	O
Blink	B-Application
license	O
(	O
GNU	O
GPLv3	O
with	O
an	O
exception	O
to	O
permit	O
the	O
inclusion	O
of	O
commercial	O
proprietary	B-Application
modules	O
)	O
.	O
</s>
<s>
The	O
software	O
is	O
written	O
in	O
Python	B-Language
for	O
macOS	B-Application
's	O
Cocoa	B-Operating_System
,	O
with	O
a	O
later	O
port	O
to	O
Qt	B-Language
for	O
supporting	O
Microsoft	B-Application
Windows	I-Application
,	O
Linux	B-Application
,	O
AmigaOS	B-Application
.	O
</s>
<s>
Blink	B-Application
is	O
based	O
on	O
the	O
Session	B-Application
Initiation	I-Application
Protocol	I-Application
,	O
and	O
beyond	O
voice	B-Application
over	I-Application
IP	I-Application
,	O
its	O
features	O
also	O
include	O
video	O
,	O
instant	B-Application
messaging	I-Application
,	O
file	B-Protocol
transfer	I-Protocol
and	O
multi-party	O
conferencing	O
sessions	O
based	O
on	O
MSRP	B-Protocol
protocol	I-Protocol
,	O
remote	O
desktop	O
sharing	O
using	O
RFB	B-Protocol
protocol	I-Protocol
(	O
VNC	O
)	O
,	O
and	O
SIMPLE	O
presence	O
using	O
XCAP	B-Language
protocol	O
.	O
</s>
<s>
Compatible	O
with	O
Asterix	B-Language
.	O
</s>
<s>
The	O
Linux	B-Application
and	O
macOS	B-Application
version	O
of	O
Blink	B-Application
implement	O
OTR	B-Protocol
protocol	I-Protocol
end-to-end	O
encryption	O
and	O
peer	O
verification	O
for	O
chat	O
media	O
.	O
</s>
<s>
All	O
versions	O
provide	O
audio	O
and	O
video	O
media	O
encryption	O
using	O
ZRTP	B-Protocol
.	O
</s>
