<s>
QVD	B-Application
is	O
an	O
open-source	B-Application
virtual	B-Protocol
desktop	I-Protocol
infrastructure	I-Protocol
(	O
VDI	O
)	O
product	O
built	O
on	O
Linux	B-Application
.	O
</s>
<s>
Its	O
main	O
purpose	O
is	O
to	O
provide	O
remote	B-Protocol
desktops	I-Protocol
to	O
users	O
.	O
</s>
<s>
QVD	B-Application
can	O
support	O
any	O
Linux	B-Application
Desktop	O
that	O
runs	O
on	O
top	O
of	O
X11	B-Operating_System
;	O
this	O
includes	O
GNOME	B-Application
,	O
KDE	B-Application
,	O
Xfce	B-Language
and	O
LXDE	B-Language
desktops	O
.	O
</s>
<s>
QVD	B-Application
clients	O
are	O
available	O
for	O
Windows	O
,	O
Linux	B-Application
,	O
macOS	B-Application
and	O
Android	B-Application
.	O
</s>
<s>
The	O
server	B-Application
software	I-Application
can	O
run	O
both	O
on	O
a	O
single-node	O
configuration	O
or	O
in	O
a	O
multi-node	O
configuration	O
.	O
</s>
<s>
In	O
case	O
of	O
the	O
latter	O
,	O
the	O
user	O
sessions	O
(	O
or	O
virtual	B-Architecture
machines	I-Architecture
)	O
are	O
automatically	O
distributed	O
along	O
the	O
running	O
nodes	O
.	O
</s>
<s>
Several	O
back-ends	O
are	O
available	O
for	O
authentication	O
and	O
new	O
ones	O
can	O
be	O
independently	O
developed	O
as	O
plugins	B-Application
.	O
</s>
<s>
NX	B-Application
libraries	O
are	O
used	O
to	O
reduce	O
the	O
network	O
traffic	O
resulting	O
in	O
very	O
low	O
bandwidth	O
requirements	O
for	O
most	O
common	O
corporate	O
desktop	O
usage	O
,	O
e.g.	O
</s>
<s>
QVD	B-Application
can	O
run	O
virtual	B-Architecture
machines	I-Architecture
using	O
KVM	B-Application
or	O
LXC	B-Application
.	O
</s>
<s>
KVM	B-Application
allows	O
for	O
a	O
complete	O
isolation	O
between	O
the	O
host	O
and	O
the	O
guest	O
virtual	B-Architecture
machines	I-Architecture
.	O
</s>
<s>
LXC	B-Application
on	O
the	O
other	O
hand	O
,	O
runs	O
the	O
virtual	O
machined	O
inside	O
isolated	O
containers	O
inside	O
the	O
host	O
.	O
</s>
<s>
Administration	O
of	O
the	O
platform	O
can	O
be	O
performed	O
through	O
a	O
web	B-Application
app	I-Application
or	O
using	O
the	O
provided	O
command	B-Application
line	I-Application
utilities	O
.	O
</s>
<s>
Provisioning	B-Operating_System
of	O
new	O
users	O
can	O
be	O
automated	O
.	O
</s>
<s>
QVD	B-Application
is	O
composed	O
of	O
actors	O
and	O
components	O
.	O
</s>
<s>
The	O
QVD	B-Application
's	O
actors	O
are	O
:	O
</s>
<s>
Virtual	B-Architecture
machines	I-Architecture
:	O
Running	O
Linux	B-Application
desktops	O
and	O
owned	O
by	O
the	O
users	O
,	O
these	O
VMs	O
runs	O
on	O
a	O
virtual	B-Architecture
machine	I-Architecture
on	O
Linux	B-Application
nodes	O
.	O
</s>
<s>
The	O
QVD	B-Application
components	O
are	O
:	O
</s>
<s>
QVD-Client	O
:	O
The	O
QVD	B-Application
client	O
software	O
that	O
connects	O
with	O
and	O
displays	O
the	O
user	O
's	O
desktop	O
from	O
the	O
server	B-Application
.	O
</s>
<s>
QVD	B-Application
currently	O
has	O
clients	O
for	O
Windows	O
,	O
Linux	B-Application
,	O
OS	O
X	B-Operating_System
(	O
Beta	O
)	O
,	O
and	O
Android	B-Application
.	O
</s>
<s>
QVD-L7R	O
:	O
Level	O
7	O
router	O
.	O
</s>
<s>
In	O
charge	O
to	O
balance	O
the	O
connections	O
from	O
the	O
QVD-Client	O
to	O
the	O
Virtual	B-Architecture
Machines	I-Architecture
and	O
the	O
responsibility	O
for	O
login	O
user	O
before	O
they	O
went	O
into	O
their	O
Virtual	B-Architecture
Machines	I-Architecture
.	O
</s>
<s>
QVD-HKD	O
:	O
House	O
keeping	O
daemon	O
.	O
</s>
<s>
Responsible	O
to	O
interact	O
with	O
the	O
Virtual	B-Architecture
Machines	I-Architecture
,	O
starting	O
,	O
stopping	O
,	O
and	O
update	O
the	O
VM	O
's	O
status	O
in	O
the	O
QVD	B-Application
Database	O
.	O
</s>
<s>
Currently	O
it	O
supports	O
KVM	B-Application
and	O
LXC	B-Application
as	O
their	O
virtualization	O
models	O
.	O
</s>
<s>
QVD-Database	O
:	O
Holds	O
the	O
status	O
for	O
all	O
users	O
,	O
Virtual	B-Architecture
Machines	I-Architecture
,	O
images	O
,	O
hosts	O
.	O
</s>
<s>
QVD-Administrative	O
tools	O
:	O
Composed	O
by	O
CLI	O
and	O
the	O
WAT	O
(	O
Web	O
administration	O
tool	O
)	O
that	O
provides	O
an	O
easy	O
and	O
simple	O
way	O
to	O
administrate	O
the	O
whole	O
platform	O
,	O
from	O
a	O
couple	O
of	O
nodes	O
to	O
hundreds	O
.	O
</s>
<s>
QVD-VMA	O
:	O
The	O
agent	O
that	O
runs	O
in	O
the	O
Virtual	B-Architecture
Machine	I-Architecture
,	O
allowing	O
users	O
to	O
connect	O
,	O
enable	O
printer	O
sharing	O
,	O
audio	O
,	O
hooks	O
,	O
etc	O
.	O
</s>
<s>
QVD	B-Application
1.x	O
and	O
2.x	O
were	O
versions	O
of	O
the	O
product	O
based	O
on	O
FreeNX	B-Application
tailored	O
for	O
a	O
specific	O
client	O
and	O
never	O
publicly	O
released	O
.	O
</s>
<s>
QVD	B-Application
3.0	O
was	O
released	O
at	O
May	O
2011	O
.	O
</s>
<s>
Able	O
to	O
provide	O
Linux	B-Application
remote	B-Protocol
desktops	I-Protocol
to	O
users	O
.	O
</s>
<s>
Supported	O
on	O
Ubuntu	B-Operating_System
Linux	I-Operating_System
.	O
</s>
<s>
KVM	B-Application
was	O
used	O
as	O
the	O
hypervisor	O
.	O
</s>
<s>
The	O
NX	B-Application
libraries	O
were	O
used	O
to	O
reduce	O
bandwidth	O
usage	O
.	O
</s>
<s>
QVD	B-Application
3.1	O
was	O
released	O
in	O
October	O
2012	O
.	O
</s>
<s>
The	O
main	O
addition	O
in	O
this	O
version	O
was	O
the	O
support	O
for	O
Linux	B-Application
containers	O
.	O
</s>
<s>
Support	O
for	O
SuSE	O
Linux	B-Application
Enterprise	O
Edition	O
(	O
SLES	O
)	O
platform	O
.	O
</s>
<s>
QVD	B-Application
3.2	O
was	O
released	O
by	O
December	O
2012	O
.	O
</s>
<s>
Support	O
for	O
Btrfs	B-Operating_System
as	O
the	O
storage	O
back-end	O
.	O
</s>
<s>
to	O
support	O
serial	B-Protocol
port	I-Protocol
redirections	O
or	O
VPN	B-Application
.	O
</s>
<s>
QVD	B-Application
3.4	O
was	O
released	O
by	O
January	O
2014	O
.	O
</s>
<s>
QVD	B-Application
Spy	O
to	O
shadow	O
sessions	O
in	O
order	O
to	O
provide	O
support	O
to	O
the	O
user	O
.	O
</s>
<s>
QVD	B-Application
3.5	O
was	O
released	O
by	O
January	O
2015	O
.	O
</s>
<s>
QVD	B-Application
4.0	O
was	O
released	O
by	O
January	O
2016	O
.	O
</s>
<s>
QVD	B-Application
4.1	O
was	O
released	O
by	O
September	O
2018	O
.	O
</s>
<s>
QVD	B-Application
4.2	O
was	O
released	O
by	O
October	O
2020	O
.	O
</s>
<s>
USBIP	O
for	O
the	O
linux	B-Application
client	O
.	O
</s>
