<s>
Syncthing	B-Language
is	O
a	O
free	B-Application
,	O
open-source	B-Application
peer-to-peer	O
file	B-Application
synchronization	I-Application
application	O
available	O
for	O
Windows	B-Application
,	O
macOS	B-Operating_System
,	O
Linux	B-Application
,	O
Android	B-Application
,	O
Solaris	B-Application
,	O
Darwin	O
,	O
and	O
BSD	B-Operating_System
.	O
</s>
<s>
Syncthing	B-Language
is	O
written	O
in	O
Go	B-Application
and	O
implements	O
its	O
own	O
,	O
equally	O
free	B-Application
Block	O
Exchange	O
Protocol	O
.	O
</s>
<s>
Syncthing	B-Language
is	O
a	O
BYO	O
cloud	B-Architecture
model	O
where	O
the	O
users	O
provide	O
the	O
hardware	O
that	O
the	O
software	O
runs	O
on	O
.	O
</s>
<s>
It	O
supports	O
IPv6	B-Protocol
and	O
,	O
for	O
those	O
on	O
IPv4	O
networks	O
,	O
NAT	B-Protocol
punching	O
and	O
relaying	O
are	O
offered	O
.	O
</s>
<s>
Devices	O
connecting	O
to	O
each	O
other	O
require	O
explicit	O
approval	O
(	O
unless	O
using	O
the	O
Introducer	O
feature	O
)	O
which	O
increases	O
the	O
security	O
of	O
the	O
mesh	B-Architecture
.	O
</s>
<s>
All	O
data	O
,	O
whether	O
transferred	O
directly	O
between	O
devices	O
or	O
via	O
relays	O
,	O
is	O
encrypted	O
using	O
TLS	B-Protocol
.	O
</s>
<s>
Efficient	O
syncing	O
is	O
achieved	O
via	O
compression	O
of	O
metadata	O
or	O
all	O
transfer	O
data	O
,	O
block	O
re-use	O
and	O
lightweight	O
scanning	O
for	O
changed	O
files	O
,	O
once	O
a	O
full	O
hash	B-Error_Name
has	O
been	O
computed	O
and	O
saved	O
.	O
</s>
<s>
Syncthing	B-Language
offers	O
send-only	O
and	O
receive-only	O
folder	O
types	O
where	O
updates	O
from	O
remote	O
devices	O
are	O
not	O
processed	O
,	O
various	O
types	O
of	O
file	O
versioning	O
(	O
trash	O
can	O
,	O
simple	O
or	O
staggered	O
versioning	O
as	O
well	O
as	O
handing	O
versioning	O
to	O
an	O
external	O
program	O
or	O
script	O
)	O
and	O
file/path	O
ignore	O
patterns	O
.	O
</s>
<s>
Two	O
different	O
SHA256	B-Algorithm
hashing	O
implementations	O
are	O
currently	O
supported	O
,	O
the	O
faster	O
of	O
which	O
will	O
be	O
used	O
dynamically	O
after	O
a	O
brief	O
benchmark	O
on	O
start-up	O
.	O
</s>
<s>
Moving	O
and	O
renaming	O
of	O
files	O
and	O
folders	O
is	O
handled	O
efficiently	O
,	O
with	O
Syncthing	B-Language
intelligently	O
processing	O
these	O
operations	O
rather	O
than	O
re-downloading	O
data	O
from	O
scratch	O
.	O
</s>
<s>
The	O
project	O
also	O
provides	O
the	O
Syncthing	B-Language
Discovery	O
Server	O
program	O
for	O
hosting	O
one	O
's	O
own	O
discovery	O
servers	O
,	O
which	O
can	O
be	O
used	O
alongside	O
,	O
or	O
as	O
a	O
replacement	O
of	O
the	O
public	O
servers	O
.	O
</s>
<s>
The	O
network	O
of	O
community-contributed	O
relay	O
servers	O
allows	O
devices	O
that	O
are	O
both	O
behind	O
different	O
IPv4	O
NAT	B-Protocol
firewalls	O
to	O
be	O
able	O
to	O
communicate	O
by	O
relaying	O
encrypted	O
data	O
via	O
a	O
third	O
party	O
.	O
</s>
<s>
The	O
relaying	O
performed	O
is	O
similar	O
in	O
nature	O
to	O
the	O
TURN	B-Protocol
protocol	O
,	O
with	O
the	O
traffic	O
TLS-encrypted	O
end-to-end	O
between	O
devices	O
(	O
thus	O
even	O
the	O
relay	O
server	O
cannot	O
see	O
the	O
data	O
,	O
only	O
the	O
encrypted	O
stream	O
)	O
.	O
</s>
<s>
Syncthing	B-Language
will	O
automatically	O
switch	O
from	O
relaying	O
to	O
direct	O
device-to-device	O
connections	O
if	O
it	O
discovers	O
that	O
a	O
direct	O
connection	O
has	O
become	O
available	O
.	O
</s>
<s>
Syncthing	B-Language
can	O
be	O
used	O
without	O
any	O
connection	O
to	O
the	O
project	O
or	O
community	O
's	O
servers	O
:	O
upgrades	O
,	O
opt-in	O
usage	O
data	O
,	O
discovery	O
and	O
relaying	O
can	O
all	O
be	O
disabled	O
and/or	O
configured	O
independently	O
,	O
thus	O
the	O
mesh	B-Architecture
and	O
its	O
infrastructure	O
can	O
all	O
be	O
run	O
in	O
a	O
closed	O
system	O
for	O
privacy	O
or	O
confidentiality	O
.	O
</s>
<s>
Syncthing	B-Language
must	O
be	O
configured	O
via	O
a	O
web	O
browser	O
either	O
locally	O
or	O
remotely	O
(	O
and	O
supports	O
access	O
via	O
proxy	O
server	O
)	O
,	O
the	O
REST	O
and	O
Events	O
APIs	O
or	O
one	O
of	O
the	O
community-contributed	O
wrapper	O
programs	O
.	O
</s>
<s>
In	O
episode	O
456	O
of	O
SecurityNow	O
!,	O
host	O
Steve	O
Gibson	O
praised	O
Syncthing	B-Language
as	O
a	O
potential	O
open-source	B-Application
replacement	O
for	O
BitTorrent	O
Sync	O
,	O
and	O
again	O
referenced	O
it	O
in	O
episodes	O
603	O
,	O
698	O
,	O
727	O
,	O
and	O
in	O
more	O
detail	O
in	O
episodes	O
734	O
and	O
781	O
.	O
</s>
<s>
A	O
reviewer	O
in	O
LWN	O
writes	O
"	O
Syncthing	B-Language
leaves	O
a	O
favorable	O
impression	O
.	O
</s>
<s>
But	O
they	O
have	O
also	O
done	O
the	O
work	O
to	O
make	O
it	O
all	O
easy	O
to	O
set	O
up	O
and	O
make	O
use	O
of	O
—	O
the	O
place	O
where	O
a	O
lot	O
of	O
free-software	B-Application
projects	O
seem	O
to	O
fall	O
down	O
.	O
</s>
<s>
In	O
October	O
2014	O
it	O
was	O
announced	O
by	O
the	O
original	O
author	O
that	O
Syncthing	B-Language
was	O
being	O
rebranded	O
as	O
"	O
Pulse	O
"	O
.	O
</s>
<s>
However	O
,	O
on	O
November	O
17	O
,	O
the	O
developer	O
decided	O
not	O
to	O
change	O
Syncthing	B-Language
to	O
Pulse	O
and	O
is	O
no	O
longer	O
working	O
with	O
ind.ie	O
.	O
</s>
<s>
ie	O
's	O
Pulse	O
is	O
now	O
an	O
officially	O
sanctioned	O
fork	O
of	O
Syncthing	B-Language
.	O
</s>
<s>
On	O
22	O
April	O
2015	O
,	O
0.11.0	O
was	O
released	O
and	O
it	O
introduced	O
conflict	O
handling	O
,	O
language	O
selection	O
in	O
the	O
UI	O
,	O
CPU	O
usage	O
and	O
synching	O
speed	O
improvements	O
,	O
Long	O
filename	O
support	O
on	O
Windows	B-Application
,	O
automatic	O
restarting	O
when	O
there	O
is	O
a	O
problem	O
for	O
example	O
the	O
drive	O
being	O
inaccessible	O
,	O
and	O
support	O
for	O
external	O
versioning	O
software	O
.	O
</s>
<s>
0.11	O
is	O
not	O
backwards	O
compatible	O
with	O
older	O
versions	O
of	O
Syncthing	B-Language
.	O
</s>
<s>
Because	O
of	O
changes	O
to	O
the	O
REST	O
API	O
Syncthing	B-Language
clients	O
that	O
were	O
on	O
0.10.x	O
would	O
n't	O
automatically	O
update	O
to	O
0.11	O
as	O
it	O
was	O
n't	O
compatible	O
with	O
a	O
lot	O
of	O
the	O
3rd	O
party	O
integrations	O
at	O
the	O
time	O
of	O
its	O
release	O
.	O
</s>
<s>
0.13.0	O
like	O
many	O
of	O
the	O
older	O
releases	O
of	O
Syncthing	B-Language
is	O
incompatible	O
with	O
clients	O
that	O
are	O
running	O
version	O
0.12.x	O
and	O
below	O
.	O
</s>
<s>
1.2.0	O
introduces	O
support	O
for	O
QUIC	B-Protocol
,	O
can	O
now	O
perform	O
automatic	O
crash	O
reporting	O
and	O
deprecates	O
small	O
/	O
fixed	O
blocks	O
.	O
</s>
<s>
1.2.0	O
also	O
dropped	O
support	O
for	O
communicating	O
with	O
Syncthing	B-Language
clients	O
that	O
are	O
running	O
0.14.45	O
or	O
older	O
.	O
</s>
<s>
1.8.0	O
adds	O
an	O
experimental	O
folder	O
option	O
that	O
allows	O
users	O
to	O
specify	O
how	O
file	O
changes	O
should	O
be	O
saved	O
on	O
Copy-on-write	B-Language
file	O
systems	O
and	O
also	O
adds	O
TCP	O
hole	O
punching	O
support	O
.	O
</s>
