<s>
vsf	B-Language
tpd	I-Language
,	O
(	O
or	O
very	O
secure	B-Protocol
FTP	I-Protocol
daemon	O
)	O
,	O
is	O
an	O
FTP	B-Protocol
server	I-Protocol
for	O
Unix-like	B-Operating_System
systems	I-Operating_System
,	O
including	O
Linux	B-Application
.	O
</s>
<s>
It	O
is	O
the	O
default	O
FTP	B-Protocol
server	I-Protocol
in	O
the	O
Ubuntu	B-Operating_System
,	O
CentOS	O
,	O
Fedora	O
,	O
NimbleX	O
,	O
Slackware	B-Application
and	O
RHEL	O
Linux	B-Application
distributions	O
.	O
</s>
<s>
It	O
is	O
licensed	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
.	O
</s>
<s>
It	O
supports	O
IPv6	B-Protocol
,	O
TLS	B-Protocol
and	O
FTPS	B-Protocol
(	O
explicit	O
since	O
2.0.0	O
and	O
implicit	O
since	O
2.1.0	O
)	O
.	O
</s>
<s>
Since	O
then	O
,	O
the	O
site	O
was	O
moved	O
to	O
Google	B-Application
App	I-Application
Engine	I-Application
.	O
</s>
