<s>
Snap	B-Application
is	O
a	O
software	O
packaging	B-Application
and	O
deployment	B-Application
system	O
developed	O
by	O
Canonical	O
for	O
operating	B-General_Concept
systems	I-General_Concept
that	O
use	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
and	O
the	O
systemd	B-Application
init	B-Operating_System
system	I-Operating_System
.	O
</s>
<s>
The	O
packages	O
,	O
called	O
snaps	B-Application
,	O
and	O
the	O
tool	O
for	O
using	O
them	O
,	O
snapd	B-Application
,	O
work	O
across	O
a	O
range	O
of	O
Linux	B-Application
distributions	I-Application
and	O
allow	O
upstream	B-General_Concept
software	O
developers	O
to	O
distribute	O
their	O
applications	O
directly	O
to	O
users	O
.	O
</s>
<s>
Snaps	B-Application
are	O
self-contained	B-Application
applications	O
running	O
in	O
a	O
sandbox	O
with	O
mediated	O
access	O
to	O
the	O
host	O
system	O
.	O
</s>
<s>
Snap	B-Application
was	O
originally	O
released	O
for	O
cloud	B-Architecture
applications	I-Architecture
but	O
was	O
later	O
ported	O
to	O
also	O
work	O
for	O
Internet	B-Operating_System
of	I-Operating_System
Things	I-Operating_System
devices	O
and	O
desktop	O
applications	O
.	O
</s>
<s>
The	O
Snap	B-Application
Store	I-Application
allows	O
developers	O
to	O
publish	O
their	O
snap-packaged	O
applications	O
.	O
</s>
<s>
All	O
apps	O
uploaded	O
to	O
the	O
Snap	B-Application
Store	I-Application
undergo	O
automatic	O
testing	O
,	O
including	O
a	O
malware	O
scan	O
.	O
</s>
<s>
When	O
this	O
issue	O
was	O
found	O
,	O
Canonical	O
removed	O
the	O
applications	O
from	O
the	O
Snap	B-Application
Store	I-Application
and	O
transferred	O
ownership	O
of	O
the	O
Snaps	B-Application
to	O
a	O
trusted	O
third-party	O
which	O
re-published	O
the	O
Snaps	B-Application
without	O
the	O
miner	O
present	O
.	O
</s>
<s>
Although	O
the	O
Snap	B-Application
sandbox	O
reduces	O
the	O
impact	O
of	O
a	O
malicious	O
app	O
,	O
Canonical	O
recommends	O
users	O
only	O
install	O
Snaps	B-Application
from	O
publishers	O
trusted	O
by	O
the	O
user	O
.	O
</s>
<s>
Snaps	B-Application
are	O
self-contained	B-Application
packages	O
that	O
work	O
across	O
a	O
range	O
of	O
Linux	B-Application
distributions	I-Application
.	O
</s>
<s>
This	O
is	O
unlike	O
traditional	O
Linux	B-Application
package	B-Application
management	I-Application
approaches	O
,	O
which	O
require	O
specifically	O
adapted	O
packages	O
for	O
each	O
Linux	B-Application
distribution	I-Application
.	O
</s>
<s>
The	O
snap	B-Application
file	O
format	O
is	O
a	O
single	O
compressed	O
filesystem	B-Application
using	O
the	O
SquashFS	B-Application
format	O
with	O
the	O
extension	O
.snap	B-Application
.	O
</s>
<s>
This	O
filesystem	B-Application
contains	O
the	O
application	O
,	O
libraries	O
it	O
depends	O
on	O
,	O
and	O
declarative	O
metadata	O
.	O
</s>
<s>
This	O
metadata	O
is	O
interpreted	O
by	O
snapd	B-Application
to	O
set	O
up	O
an	O
appropriately	O
shaped	O
secure	O
sandbox	O
for	O
that	O
application	O
.	O
</s>
<s>
After	O
installation	O
,	O
the	O
snap	B-Application
is	O
mounted	O
by	O
the	O
host	O
operating	B-General_Concept
system	I-General_Concept
and	O
decompressed	O
on	O
the	O
fly	O
when	O
the	O
files	O
are	O
used	O
.	O
</s>
<s>
Although	O
this	O
has	O
the	O
advantage	O
that	O
snaps	B-Application
use	O
less	O
disk	O
space	O
,	O
it	O
also	O
means	O
some	O
large	O
applications	O
start	O
more	O
slowly	O
.	O
</s>
<s>
A	O
significant	O
difference	O
between	O
Snap	B-Application
and	O
other	O
universal	O
Linux	B-Application
packaging	B-Application
formats	O
such	O
as	O
Flatpak	B-Language
is	O
that	O
Snap	B-Application
supports	O
any	O
class	O
of	O
Linux	B-Application
application	O
such	O
as	O
desktop	O
applications	O
,	O
server	O
tools	O
,	O
IoT	B-Operating_System
apps	O
and	O
even	O
system	O
services	O
such	O
as	O
the	O
printer	O
driver	O
stack	O
.	O
</s>
<s>
To	O
ensure	O
this	O
,	O
Snap	B-Application
relies	O
on	O
systemd	B-Application
for	O
features	O
such	O
as	O
running	O
socket-activated	O
system	O
services	O
in	O
a	O
Snap	B-Application
.	O
</s>
<s>
This	O
causes	O
Snap	B-Application
to	O
work	O
best	O
only	O
on	O
distributions	O
that	O
can	O
adopt	O
that	O
init	B-Operating_System
system	I-Operating_System
.	O
</s>
<s>
Applications	O
in	O
a	O
Snap	B-Application
run	O
in	O
a	O
container	O
with	O
limited	O
access	O
to	O
the	O
host	O
system	O
.	O
</s>
<s>
These	O
interfaces	O
mediate	O
regular	O
Linux	B-Application
APIs	O
so	O
that	O
applications	O
can	O
function	O
in	O
the	O
sandbox	O
without	O
needing	O
to	O
be	O
rewritten	O
.	O
</s>
<s>
Desktop	O
applications	O
can	O
also	O
use	O
the	O
XDG	O
Desktop	O
Portals	O
,	O
a	O
standardized	O
API	O
originally	O
created	O
by	O
the	O
Flatpak	B-Language
project	O
to	O
give	O
sandboxed	O
desktop	O
applications	O
access	O
to	O
host	O
resources	O
.	O
</s>
<s>
These	O
portals	O
often	O
provide	O
a	O
better	O
user	O
experience	O
compared	O
to	O
the	O
native	O
Linux	B-Application
APIs	O
because	O
they	O
prompt	O
the	O
user	O
for	O
permission	O
to	O
use	O
resources	O
such	O
as	O
a	O
webcam	O
at	O
the	O
time	O
the	O
application	O
uses	O
them	O
.	O
</s>
<s>
The	O
Snap	B-Application
sandbox	O
also	O
supports	O
sharing	O
data	O
and	O
Unix	B-Protocol
sockets	I-Protocol
between	O
Snaps	B-Application
.	O
</s>
<s>
This	O
is	O
often	O
used	O
to	O
share	O
common	O
libraries	O
and	O
application	O
frameworks	O
between	O
Snaps	B-Application
to	O
reduce	O
the	O
size	O
of	O
Snaps	B-Application
by	O
avoiding	O
duplication	O
.	O
</s>
<s>
The	O
Snap	B-Application
sandbox	O
heavily	O
relies	O
on	O
the	O
AppArmor	O
Linux	B-Application
Security	I-Application
Module	I-Application
from	O
the	O
upstream	B-General_Concept
Linux	B-Operating_System
kernel	I-Operating_System
.	O
</s>
<s>
Because	O
only	O
one	O
"	O
major	O
"	O
Linux	B-Application
Security	I-Application
Module	I-Application
(	O
LSM	O
)	O
can	O
be	O
active	O
at	O
the	O
same	O
time	O
,	O
the	O
Snap	B-Application
sandbox	O
is	O
much	O
less	O
secure	O
when	O
another	O
major	O
LSM	O
is	O
enabled	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
on	O
distributions	O
such	O
as	O
Fedora	O
which	O
enable	O
SELinux	B-Application
by	O
default	O
,	O
the	O
Snap	B-Application
sandbox	O
is	O
heavily	O
degraded	O
.	O
</s>
<s>
The	O
Snap	B-Application
sandbox	O
prevents	O
snapped	O
desktop	O
applications	O
from	O
accessing	O
the	O
themes	O
of	O
the	O
host	O
operating	B-General_Concept
system	I-General_Concept
to	O
prevent	O
compatibility	O
issues	O
.	O
</s>
<s>
In	O
order	O
for	O
Snaps	B-Application
to	O
use	O
a	O
theme	O
,	O
it	O
also	O
needs	O
to	O
be	O
packaged	O
in	O
a	O
separate	O
Snap	B-Application
.	O
</s>
<s>
Many	O
popular	O
themes	O
are	O
packaged	O
by	O
the	O
Snap	B-Application
developers	O
but	O
some	O
themes	O
are	O
not	O
supported	O
yet	O
and	O
uncommon	O
themes	O
have	O
to	O
be	O
installed	O
manually	O
.	O
</s>
<s>
If	O
a	O
theme	O
is	O
not	O
available	O
as	O
a	O
Snap	B-Application
package	I-Application
,	O
users	O
have	O
to	O
resort	O
to	O
choosing	O
the	O
best	O
matching	O
theme	O
available	O
.	O
</s>
<s>
Work	O
is	O
ongoing	O
to	O
make	O
it	O
easier	O
for	O
third	O
parties	O
to	O
package	O
themes	O
in	O
a	O
Snap	B-Application
and	O
to	O
automatically	O
install	O
uncommon	O
system	O
themes	O
.	O
</s>
<s>
Multiple	O
times	O
a	O
day	O
,	O
snapd	B-Application
checks	O
for	O
available	O
updates	O
of	O
all	O
Snaps	B-Application
and	O
installs	O
them	O
in	O
the	O
background	O
using	O
an	O
atomic	B-General_Concept
operation	I-General_Concept
.	O
</s>
<s>
Updates	O
can	O
be	O
reverted	O
and	O
use	O
delta	B-Algorithm
encoding	I-Algorithm
to	O
reduce	O
their	O
download	O
size	O
.	O
</s>
<s>
When	O
installing	O
an	O
application	O
,	O
Snap	B-Application
defaults	O
to	O
using	O
the	O
latest/stable	O
channel	O
,	O
which	O
will	O
automatically	O
update	O
to	O
new	O
major	O
releases	O
of	O
the	O
software	O
when	O
they	O
become	O
available	O
.	O
</s>
<s>
Snapcraft	B-Application
is	O
a	O
tool	O
for	O
developers	O
to	O
package	O
their	O
programs	O
in	O
the	O
Snap	B-Application
format	O
.	O
</s>
<s>
It	O
runs	O
on	O
any	O
Linux	B-Application
distribution	I-Application
supported	O
by	O
Snap	B-Application
,	O
macOS	B-Application
and	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
Snapcraft	B-Application
builds	O
the	O
packages	O
in	O
a	O
Virtual	B-Architecture
Machine	I-Architecture
using	O
Multipass	O
,	O
in	O
order	O
to	O
ensure	O
the	O
result	O
of	O
a	O
build	O
is	O
the	O
same	O
,	O
regardless	O
of	O
which	O
distribution	O
or	O
operating	B-General_Concept
system	I-General_Concept
it	O
is	O
built	O
on	O
.	O
</s>
<s>
Snapcraft	B-Application
supports	O
multiple	O
build	O
tools	O
and	O
programming	O
languages	O
,	O
such	O
as	O
Go	B-Application
,	O
Java	B-Language
,	O
JavaScript	B-Language
,	O
Python	B-Language
,	O
C/C	O
++	O
and	O
Rust	B-Application
.	O
</s>
<s>
It	O
also	O
allows	O
importing	O
application	O
metadata	O
from	O
multiple	O
sources	O
such	O
as	O
AppStream	B-Application
,	O
git	B-Application
,	O
shell	B-Language
scripts	I-Language
and	O
setup.py	O
files	O
.	O
</s>
<s>
Snap	B-Application
initially	O
only	O
supported	O
the	O
all-Snap	O
Ubuntu	O
Core	O
distribution	O
,	O
but	O
in	O
June	O
2016	O
,	O
it	O
was	O
ported	O
to	O
a	O
wide	O
range	O
of	O
Linux	B-Application
distributions	I-Application
to	O
become	O
a	O
format	O
for	O
universal	O
Linux	B-Application
packages	O
.	O
</s>
<s>
Snap	B-Application
requires	O
Systemd	B-Application
which	O
is	O
available	O
in	O
most	O
,	O
but	O
not	O
all	O
,	O
Linux	B-Application
distributions	I-Application
.	O
</s>
<s>
Other	O
Unix-like	B-Operating_System
systems	I-Operating_System
(	O
e.g.	O
</s>
<s>
FreeBSD	B-Operating_System
)	O
are	O
not	O
supported	O
.	O
</s>
<s>
ChromeOS	B-Operating_System
does	O
not	O
support	O
Snap	B-Application
directly	O
,	O
only	O
through	O
Linux	B-Application
distributions	I-Application
installed	O
in	O
it	O
that	O
support	O
Snap	B-Application
,	O
such	O
as	O
Gallium	O
OS	O
.	O
</s>
<s>
Ubuntu	O
and	O
its	O
official	O
derivatives	O
pre-install	O
Snap	B-Application
by	O
default	O
,	O
as	O
well	O
as	O
other	O
Ubuntu-based	O
distributions	O
such	O
as	O
KDE	B-Language
Neon	I-Language
,	O
Solus	O
,	O
and	O
Zorin	O
OS	O
.	O
</s>
<s>
While	O
other	O
official	O
Ubuntu	O
derivatives	O
such	O
as	O
Kubuntu	B-Application
,	O
Xubuntu	B-Application
,	O
and	O
Ubuntu	O
MATE	O
have	O
also	O
shipped	O
with	O
the	O
competing	O
Flatpak	B-Language
as	O
a	O
compliment	O
,	O
Canonical	O
will	O
prohibit	O
them	O
from	O
doing	O
so	O
beginning	O
with	O
Ubuntu	O
23.04	O
,	O
meaning	O
that	O
it	O
must	O
be	O
installed	O
manually	O
by	O
the	O
user	O
.	O
</s>
<s>
A	O
number	O
of	O
notable	O
desktop	O
software	O
development	O
companies	O
publish	O
their	O
software	O
in	O
the	O
Snap	B-Application
Store	I-Application
,	O
including	O
Google	B-Application
,	O
JetBrains	O
,	O
KDE	B-Application
,	O
Microsoft	O
(	O
for	O
Linux	B-Application
versions	O
of	O
e.g.	O
</s>
<s>
.NET	O
Core	O
3.1	O
,	O
Visual	B-Language
Studio	I-Language
Code	I-Language
,	O
Skype	B-Application
,	O
and	O
PowerShell	B-Application
)	O
,	O
Mozilla	B-Operating_System
and	O
Spotify	B-Application
.	O
</s>
<s>
Snaps	B-Application
are	O
also	O
used	O
in	O
Internet-of-Things	B-Operating_System
environments	O
,	O
ranging	O
from	O
consumer-facing	O
products	O
to	O
enterprise	O
device	O
management	O
gateways	O
and	O
satellite	O
communication	O
networks	O
.	O
</s>
<s>
Finally	O
,	O
Snap	B-Application
is	O
also	O
used	O
by	O
developers	O
of	O
server	O
applications	O
such	O
as	O
InfluxDB	B-Language
,	O
Kata	O
Containers	O
,	O
Nextcloud	B-General_Concept
and	O
Travis	B-Application
CI	I-Application
.	O
</s>
<s>
Snap	B-Application
has	O
received	O
mixed	O
reaction	O
from	O
the	O
developer	O
community	O
.	O
</s>
<s>
On	O
Snap	B-Application
's	O
promotional	O
site	O
,	O
Heroku	B-General_Concept
praised	O
Snap	B-Application
's	O
auto-update	O
as	O
it	O
fits	O
their	O
fast	O
release	O
schedule	O
well	O
.	O
</s>
<s>
Microsoft	O
mentions	O
its	O
ease	O
of	O
use	O
and	O
Snap	B-Application
being	O
YAML-based	O
,	O
as	O
well	O
as	O
it	O
being	O
distribution-agnostic	O
.	O
</s>
<s>
JetBrains	O
says	O
the	O
Snap	B-Application
Store	I-Application
gives	O
their	O
tools	O
more	O
exposure	O
.	O
</s>
<s>
Others	O
have	O
objected	O
to	O
the	O
closed-source	B-Application
nature	O
of	O
the	O
Snap	B-Application
Store	I-Application
.	O
</s>
<s>
Clement	B-Application
Lefebvre	I-Application
(	O
Linux	B-Application
Mint	I-Application
founder	O
and	O
project	O
leader	O
)	O
has	O
written	O
that	O
Snap	B-Application
is	O
biased	O
and	O
has	O
a	O
conflict	O
of	O
interest	O
.	O
</s>
<s>
The	O
reasons	O
he	O
cited	O
include	O
it	O
being	O
governed	O
by	O
Canonical	O
and	O
locked	O
to	O
their	O
store	O
,	O
and	O
also	O
that	O
Snap	B-Application
works	O
better	O
on	O
Ubuntu	O
than	O
on	O
other	O
distributions	O
.	O
</s>
<s>
He	O
later	O
announced	O
that	O
the	O
installing	O
of	O
Snap	B-Application
would	O
be	O
blocked	O
by	O
APT	B-Application
in	O
Linux	B-Application
Mint	I-Application
,	O
although	O
a	O
way	O
to	O
disable	O
this	O
restriction	O
would	O
be	O
documented	O
.	O
</s>
<s>
On	O
recent	O
versions	O
of	O
Ubuntu	O
,	O
Canonical	O
has	O
migrated	O
certain	O
packages	O
exclusively	O
to	O
Snap	B-Application
,	O
such	O
as	O
Chromium	B-Language
and	O
Firefox	B-Application
web	I-Application
browsers	I-Application
.	O
</s>
<s>
The	O
replacement	O
of	O
Firefox	B-Application
led	O
to	O
mixed	O
reception	O
from	O
users	O
due	O
to	O
performance	O
issues	O
with	O
the	O
Snap	B-Application
version	O
,	O
especially	O
on	O
startup	O
.	O
</s>
