<s>
Issabel	B-Protocol
is	O
open-source	O
Unified	B-Protocol
Communications	I-Protocol
PBX	O
software	O
,	O
providing	O
user-friendly	O
web-based	O
configuration	O
,	O
management	O
,	O
and	O
reporting	O
for	O
telephony	O
.	O
</s>
<s>
It	O
is	O
a	O
fork	O
of	O
the	O
open-source	O
versions	O
of	O
Elastix	B-Algorithm
,	O
developed	O
by	O
the	O
user/developer	O
community	O
when	O
3CX	O
acquired	O
Elastix	B-Algorithm
,	O
closed	O
the	O
community	O
,	O
halted	O
distribution	O
and	O
development	O
of	O
the	O
open-source	O
versions	O
,	O
and	O
released	O
a	O
proprietary	O
version	O
.	O
</s>
<s>
Issabel	B-Protocol
is	O
based	O
upon	O
open-source	O
versions	O
of	O
Elastix	B-Algorithm
,	O
Asterisk	B-Language
,	O
FreePBX	B-Application
,	O
HylaFAX	B-Device
,	O
Openfire	B-Language
and	O
Postfix	B-Application
and	O
provides	O
PBX	O
,	O
fax	O
,	O
instant	O
messaging	O
and	O
e-mail	O
server	O
functionality	O
.	O
</s>
<s>
Issabel	B-Protocol
is	O
open-source	O
software	O
licensed	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
.	O
</s>
