<s>
Flatpak	B-Language
,	O
formerly	O
known	O
as	O
xdg-app	B-Language
,	O
is	O
a	O
utility	B-Application
for	O
software	B-Application
deployment	I-Application
and	O
package	B-Application
management	I-Application
for	O
Linux	B-Operating_System
.	O
</s>
<s>
It	O
is	O
advertised	O
as	O
offering	O
a	O
sandbox	O
environment	O
in	O
which	O
users	O
can	O
run	O
application	B-Application
software	I-Application
in	O
isolation	O
from	O
the	O
rest	O
of	O
the	O
system	O
.	O
</s>
<s>
Applications	O
using	O
Flatpak	B-Language
need	O
permissions	O
to	O
have	O
access	O
to	O
resources	O
such	O
as	O
Bluetooth	B-Protocol
,	O
sound	O
(	O
with	O
PulseAudio	B-Library
)	O
,	O
network	B-Architecture
,	O
and	O
files	B-Operating_System
.	O
</s>
<s>
These	O
permissions	O
are	O
configured	O
by	O
the	O
maintainer	O
of	O
the	O
Flatpak	B-Language
and	O
can	O
be	O
added	O
or	O
removed	O
by	O
users	O
on	O
their	O
system	O
.	O
</s>
<s>
Another	O
key	O
feature	O
of	O
Flatpak	B-Language
is	O
that	O
it	O
allows	O
application	O
developers	O
to	O
directly	O
provide	O
updates	O
to	O
users	O
without	O
going	O
through	O
distributions	O
,	O
and	O
without	O
having	O
to	O
package	O
and	O
test	O
the	O
application	O
separately	O
for	O
each	O
distribution	O
.	O
</s>
<s>
Flathub	B-Language
,	O
a	O
repository	O
(	O
or	O
remote	O
source	O
in	O
the	O
Flatpak	B-Language
terminology	O
)	O
located	O
at	O
,	O
has	O
become	O
the	O
de	O
facto	O
standard	O
for	O
getting	O
applications	O
packaged	O
with	O
Flatpak	B-Language
.	O
</s>
<s>
Packages	O
are	O
added	O
to	O
it	O
by	O
both	O
the	O
Flathub	B-Language
administrators	O
and	O
the	O
developers	O
of	O
the	O
programs	O
themselves	O
(	O
though	O
the	O
admins	O
have	O
stated	O
their	O
preference	O
for	O
developer-submitted	O
apps	O
)	O
.	O
</s>
<s>
Although	O
Flathub	B-Language
is	O
the	O
de	O
facto	O
source	O
for	O
applications	O
packaged	O
with	O
Flatpak	B-Language
,	O
it	O
is	O
possible	O
to	O
host	O
a	O
Flatpak	B-Language
repository	O
that	O
is	O
independent	O
of	O
Flathub	B-Language
.	O
</s>
<s>
Flatpak	B-Language
runs	O
in	O
a	O
sandbox	O
(	O
which	O
provides	O
a	O
separate	O
,	O
ABI-stable	O
version	O
of	O
all	O
common	O
system	O
libraries	O
)	O
,	O
and	O
that	O
means	O
that	O
it	O
will	O
always	O
use	O
more	O
space	O
on	O
the	O
system	O
than	O
common	O
native	O
packages	O
.	O
</s>
<s>
However	O
,	O
this	O
is	O
not	O
a	O
concern	O
as	O
Flatpak	B-Language
uses	O
OSTree	B-Application
as	O
its	O
backend	O
which	O
can	O
deduplicate	O
matching	O
files	B-Operating_System
.	O
</s>
<s>
This	O
means	O
that	O
the	O
first	O
install	O
of	O
a	O
Flatpak	B-Language
application	O
will	O
always	O
take	O
up	O
more	O
space	O
at	O
first	O
,	O
but	O
will	O
be	O
more	O
efficient	O
as	O
the	O
user	O
installs	O
more	O
Flatpak	B-Language
packages	O
.	O
</s>
<s>
Theoretically	O
,	O
Flatpak	B-Language
apps	O
can	O
be	O
installed	O
on	O
any	O
existing	O
and	O
future	O
Linux	B-Application
distribution	I-Application
,	O
including	O
those	O
installed	O
with	O
the	O
Windows	O
Subsystem	O
for	O
Linux	B-Operating_System
compatibility	O
layer	O
,	O
so	O
long	O
as	O
and	O
OSTree	B-Application
are	O
available	O
.	O
</s>
<s>
It	O
can	O
also	O
be	O
used	O
on	O
Linux	O
kernel-based	O
systems	O
like	O
ChromeOS	B-Operating_System
.	O
</s>
<s>
The	O
hosts	O
setup	O
instructions	O
to	O
start	O
using	O
Flathub	B-Language
and	O
Flatpak	B-Language
on	O
a	O
large	O
number	O
of	O
Linux	B-Application
distributions	I-Application
.	O
</s>
