<s>
syslog-ng	B-Protocol
is	O
a	O
free	B-License
and	I-License
open-source	I-License
implementation	O
of	O
the	O
syslog	B-Protocol
protocol	O
for	O
Unix	B-Application
and	O
Unix-like	B-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
It	O
extends	O
the	O
original	O
syslogd	B-Protocol
model	O
with	O
content-based	O
filtering	O
,	O
rich	O
filtering	O
capabilities	O
,	O
flexible	O
configuration	O
options	O
and	O
adds	O
important	O
features	O
to	O
syslog	B-Protocol
,	O
like	O
using	O
TCP	B-Protocol
for	O
transport	O
.	O
</s>
<s>
As	O
of	O
today	O
,	O
syslog-ng	B-Protocol
is	O
developed	O
by	O
Balabit	O
IT	O
Security	O
Ltd	O
.	O
</s>
<s>
The	O
first	O
is	O
called	O
syslog-ng	B-Protocol
Open	O
Source	O
Edition	O
(	O
OSE	O
)	O
with	O
the	O
license	O
LGPL	B-Application
.	O
</s>
<s>
The	O
second	O
is	O
called	O
Premium	O
Edition	O
(	O
PE	O
)	O
and	O
has	O
additional	O
plugins	O
(	O
modules	O
)	O
under	O
a	O
proprietary	B-Application
license	I-Application
.	O
</s>
<s>
In	O
January	O
2018	O
,	O
syslog-ng	B-Protocol
,	O
as	O
part	O
of	O
Balabit	O
,	O
was	O
acquired	O
by	O
One	O
Identity	O
,	O
a	O
global	O
vendor	O
of	O
identity	O
and	O
access	O
management	O
solutions	O
under	O
the	O
Quest	O
Software	O
umbrella	O
.	O
</s>
<s>
The	O
syslog-ng	B-Protocol
team	O
remains	O
an	O
independent	O
business	O
within	O
the	O
One	O
Identity	O
organization	O
and	O
continues	O
to	O
develop	O
its	O
open	O
source	O
and	O
commercial	O
solutions	O
under	O
the	O
syslog-ng	B-Protocol
brand	O
.	O
</s>
<s>
syslog-ng	B-Protocol
uses	O
the	O
standard	O
BSD	B-Operating_System
syslog	B-Protocol
protocol	O
,	O
specified	O
in	O
RFC	O
3164	O
.	O
</s>
<s>
Since	O
version	O
3.0	O
syslog-ng	B-Protocol
also	O
supports	O
the	O
syslog	B-Protocol
protocol	O
specified	O
in	O
RFC	O
5424	O
.	O
syslog-ng	B-Protocol
interoperates	O
with	O
a	O
variety	O
of	O
devices	O
,	O
and	O
the	O
format	O
of	O
relayed	O
messages	O
can	O
be	O
customized	O
.	O
</s>
<s>
Extensions	O
to	O
the	O
original	O
syslog-ng	B-Protocol
protocol	O
include	O
:	O
</s>
<s>
The	O
syslog-ng	B-Protocol
project	O
began	O
in	O
1998	O
,	O
when	O
Balázs	O
Scheidler	O
,	O
the	O
primary	O
author	O
of	O
syslog-ng	B-Protocol
,	O
ported	O
the	O
existing	O
nsyslogd	O
code	O
to	O
Linux	B-Application
.	O
</s>
<s>
The	O
1.0.x	O
branch	O
of	O
syslog-ng	B-Protocol
was	O
still	O
based	O
on	O
the	O
nsyslogd	O
sources	O
and	O
are	O
available	O
in	O
the	O
syslog-ng	B-Protocol
source	O
archive	O
.	O
</s>
<s>
Right	O
after	O
the	O
release	O
of	O
syslog-ng	B-Protocol
1.0.x	O
,	O
a	O
reimplementation	O
of	O
the	O
code	O
base	O
started	O
to	O
address	O
some	O
of	O
the	O
shortcomings	O
of	O
nsyslogd	O
and	O
to	O
address	O
the	O
licensing	O
concerns	O
of	O
Darren	O
Reed	O
,	O
the	O
original	O
nsyslogd	O
author	O
.	O
</s>
<s>
This	O
time	O
around	O
,	O
syslog-ng	B-Protocol
depended	O
on	O
some	O
code	O
originally	O
developed	O
for	O
lsh	B-Algorithm
by	O
Niels	O
Möller	O
.	O
</s>
<s>
In	O
this	O
period	O
of	O
about	O
8	O
years	O
,	O
syslog-ng	B-Protocol
became	O
one	O
of	O
the	O
popular	O
alternative	O
syslog	B-Protocol
implementations	O
.	O
</s>
<s>
In	O
a	O
volunteer	O
based	O
effort	O
,	O
yet	O
another	O
rewrite	O
was	O
started	O
back	O
in	O
2001	O
,	O
dropping	O
lsh	B-Algorithm
code	O
and	O
using	O
the	O
more	O
widely	O
available	O
GLib	B-Language
library	O
.	O
</s>
<s>
Support	O
for	O
2.x	O
was	O
dropped	O
at	O
the	O
end	O
of	O
2009	O
,	O
but	O
it	O
is	O
still	O
used	O
in	O
some	O
Linux	B-Application
distributions	O
.	O
</s>
<s>
Balabit	O
,	O
the	O
company	O
behind	O
syslog-ng	B-Protocol
,	O
started	O
a	O
parallel	O
,	O
commercial	O
fork	O
of	O
syslog-ng	B-Protocol
,	O
called	O
syslog-ng	B-Protocol
Premium	O
Edition	O
.	O
</s>
<s>
Syslog-ng	B-Protocol
version	O
3.0	O
was	O
released	O
in	O
the	O
fourth	O
quarter	O
of	O
2008	O
.	O
</s>
<s>
The	O
Open	O
Source	O
Edition	O
efforts	O
focused	O
on	O
improving	O
the	O
flexibility	O
of	O
the	O
core	O
infrastructure	O
to	O
allow	O
more	O
and	O
more	O
different	O
,	O
non-syslog	O
message	O
sources	O
.	O
</s>
<s>
syslog-ng	B-Protocol
provides	O
a	O
number	O
of	O
features	O
in	O
addition	O
to	O
transporting	O
syslog	B-Protocol
messages	O
and	O
storing	O
them	O
in	O
plain	O
text	O
log	O
files	O
:	O
</s>
<s>
The	O
ability	O
to	O
correlate	O
multiple	O
incoming	O
messages	O
to	O
form	O
a	O
more	O
complex	O
,	O
correlated	O
event	O
(	O
since	O
syslog-ng	B-Protocol
OSE	O
3.2	O
)	O
;	O
</s>
<s>
syslog-ng	B-Protocol
is	O
available	O
on	O
a	O
number	O
of	O
different	O
Linux	B-Application
and	O
Unix	B-Application
distributions	O
.	O
</s>
<s>
Some	O
install	O
it	O
as	O
the	O
system	O
default	O
,	O
or	O
provide	O
it	O
as	O
a	O
package	O
that	O
replaces	O
the	O
previous	O
standard	O
syslogd	B-Protocol
.	O
</s>
<s>
Several	O
Linux	B-Application
distributions	O
that	O
used	O
syslog-ng	B-Protocol
have	O
replaced	O
it	O
with	O
rsyslog	B-Protocol
.	O
</s>
<s>
syslog-ng	B-Protocol
is	O
highly	O
portable	O
to	O
many	O
Unix	B-Application
systems	I-Application
,	O
old	O
and	O
new	O
alike	O
.	O
</s>
<s>
A	O
list	O
of	O
the	O
currently	O
known	O
to	O
work	O
Unix	B-Application
versions	O
are	O
found	O
below	O
:	O
</s>
