<s>
AppImage	B-Application
is	O
a	O
format	O
for	O
distributing	O
portable	B-Application
software	I-Application
on	O
Linux	B-Operating_System
without	O
needing	O
superuser	B-Application
permissions	O
to	O
install	B-Application
the	O
application	B-Application
.	O
</s>
<s>
It	O
tries	O
also	O
to	O
allow	O
Linux	O
distribution-agnostic	O
binary	O
software	O
deployment	O
for	O
application	B-Application
developers	I-Application
,	O
also	O
called	O
upstream	B-General_Concept
packaging	O
.	O
</s>
<s>
Released	O
first	O
in	O
2004	O
under	O
the	O
name	O
klik	B-Application
,	O
it	O
was	O
continuously	O
developed	O
,	O
then	O
renamed	O
in	O
2011	O
to	O
PortableLinuxApps	O
and	O
later	O
in	O
2013	O
to	O
AppImage	B-Application
.	O
</s>
<s>
AppImage	B-Application
aims	O
to	O
be	O
an	O
application	B-Application
deployment	O
system	O
for	O
Linux	B-Operating_System
with	O
the	O
following	O
objectives	O
:	O
simplicity	O
,	O
binary	B-General_Concept
compatibility	I-General_Concept
,	O
portability	B-Application
,	O
distro	B-Application
agnosticism	O
,	O
no	O
installation	B-Application
,	O
no	O
root	B-Application
permission	I-Application
,	O
and	O
keeping	O
the	O
underlying	O
operating	B-General_Concept
system	I-General_Concept
untouched	O
.	O
</s>
<s>
AppImage	B-Application
does	O
not	O
install	B-Application
the	O
application	B-Application
in	O
the	O
traditional	O
Linux	B-Operating_System
sense	O
.	O
</s>
<s>
Instead	O
of	O
putting	O
the	O
application	B-Application
's	O
various	O
files	O
in	O
the	O
distro	B-Application
's	O
appropriate	O
places	O
in	O
the	O
file	B-Application
system	I-Application
,	O
the	O
AppImage	B-Application
file	B-Operating_System
is	O
just	O
the	O
application	B-Application
's	O
compressed	O
image	O
.	O
</s>
<s>
When	O
it	O
runs	O
,	O
the	O
file	B-Operating_System
is	O
mounted	O
with	O
FUSE	B-Application
.	O
</s>
<s>
This	O
behavior	O
is	O
consistent	O
with	O
AppImage	B-Application
's	O
predecessors	O
,	O
klik	B-Application
and	O
PortableLinuxApps	O
.	O
</s>
<s>
It	O
uses	O
one	O
file	B-Operating_System
per	O
application	B-Application
.	O
</s>
<s>
Each	O
file	B-Operating_System
is	O
self-contained	O
:	O
it	O
includes	O
all	O
libraries	B-Library
the	O
application	B-Application
depends	B-Application
on	O
that	O
are	O
not	O
already	O
part	O
of	O
the	O
targeted	O
base-system	O
.	O
</s>
<s>
An	O
AppImage	B-Application
of	O
version	O
1.0	O
is	O
an	O
ISO	B-Application
9660	I-Application
Rock	O
Ridge	O
file	B-Operating_System
(	O
which	O
can	O
be	O
optionally	O
zisofs	O
compressed	O
)	O
containing	O
a	O
minimal	O
AppDir	B-Application
and	O
a	O
tiny	O
runtime	B-Library
.	O
</s>
<s>
(	O
Version	O
2	O
may	O
use	O
other	O
file	B-Application
system	I-Application
image	O
formats	O
like	O
SquashFS	B-Application
)	O
.	O
</s>
<s>
An	O
AppImage	B-Application
application	B-Application
can	O
be	O
added	O
to	O
a	O
live	O
CD	O
by	O
adding	O
only	O
one	O
file	B-Operating_System
to	O
the	O
live	O
CD	O
.	O
</s>
<s>
AppImage	B-Application
files	O
are	O
simpler	O
than	O
installing	O
an	O
application	B-Application
.	O
</s>
<s>
No	O
extraction	O
tools	O
are	O
needed	O
,	O
nor	O
is	O
it	O
necessary	O
to	O
modify	O
the	O
operating	B-General_Concept
system	I-General_Concept
or	O
user	O
environment	O
.	O
</s>
<s>
Regular	O
users	O
on	O
the	O
common	O
Linux	B-Application
distributions	I-Application
can	O
download	O
it	O
,	O
make	O
it	O
executable	O
,	O
and	O
run	O
it	O
.	O
</s>
<s>
AppImage	B-Application
allows	O
generation	O
of	O
embedded	O
digital	O
signature	O
,	O
which	O
need	O
to	O
be	O
verified	O
with	O
an	O
external	O
utility	O
.	O
</s>
<s>
The	O
format	O
does	O
not	O
offer	O
form	O
of	O
self-check	O
with	O
package	O
authenticity	O
verification	O
or	O
runtime	B-Library
confinement	O
by	O
sandboxing	O
.	O
</s>
<s>
AppImage	B-Application
's	O
predecessor	O
klik	B-Application
was	O
designed	O
in	O
2004	O
by	O
Simon	O
Peter	O
.	O
</s>
<s>
The	O
client-side	O
software	O
is	O
GPL-licensed	O
.	O
</s>
<s>
klik	B-Application
integrated	O
with	O
web	O
browsers	O
on	O
the	O
user	O
's	O
computer	O
.	O
</s>
<s>
Users	O
downloaded	O
and	O
installed	O
software	O
by	O
typing	O
a	O
URL	O
beginning	O
with	O
klik://	O
.	O
</s>
<s>
This	O
downloaded	O
a	O
klik	B-Application
"	O
recipe	O
"	O
file	B-Operating_System
,	O
which	O
was	O
used	O
to	O
generate	O
a	O
.cmg	B-Application
file	B-Operating_System
.	O
</s>
<s>
For	O
main	O
ingredients	O
,	O
usually	O
pre-built	O
.deb	O
packages	O
from	O
Debian	O
Stable	O
repositories	O
were	O
fed	O
into	O
the	O
recipe	O
's	O
.cmg	B-Application
generation	O
process	O
.	O
</s>
<s>
With	O
klik	B-Application
,	O
only	O
eight	O
programs	O
could	O
be	O
run	O
at	O
once	O
because	O
of	O
the	O
limitation	O
of	O
mounting	O
compressed	O
images	O
with	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
,	O
unless	O
FUSE	B-Application
was	O
used	O
.	O
</s>
<s>
The	O
file	B-Operating_System
was	O
remounted	O
each	O
time	O
the	O
program	O
is	O
run	O
,	O
meaning	O
the	O
user	O
could	O
remove	O
the	O
program	O
by	O
simply	O
deleting	O
the	O
.cmg	B-Application
file	B-Operating_System
.	O
</s>
<s>
A	O
next	O
version	O
,	O
klik2	B-Application
,	O
was	O
in	O
development	O
;	O
and	O
would	O
natively	O
incorporate	O
the	O
FUSE	B-Application
kernel	B-Operating_System
module	O
,	O
but	O
it	O
never	O
reached	O
past	O
the	O
beta	O
stage	O
.	O
</s>
<s>
Around	O
2011	O
,	O
the	O
klik	B-Application
project	O
went	O
dormant	O
and	O
the	O
homepage	O
went	O
offline	O
for	O
some	O
time	O
.	O
</s>
<s>
Around	O
2013	O
,	O
the	O
software	O
was	O
renamed	O
again	O
from	O
portableLinuxApps	O
to	O
AppImage	B-Application
;	O
the	O
license	O
became	O
the	B-License
MIT	I-License
license	I-License
.	O
</s>
<s>
AppImage	B-Application
is	O
the	O
format	O
and	O
AppImageKit	B-Application
is	O
a	O
concrete	O
open	O
source	O
implementation	O
.	O
</s>
<s>
The	O
development	O
happens	O
in	O
a	O
GitHub	B-Application
repository	O
.	O
</s>
<s>
Klik	B-Application
was	O
in	O
2007	O
the	O
inspiration	O
for	O
Alexander	O
Larsson	O
's	O
glick	O
project	O
,	O
the	O
precursor	O
of	O
Flatpak	B-Language
,	O
which	O
was	O
released	O
in	O
2016	O
.	O
</s>
<s>
Many	O
open	O
source	O
software	O
projects	O
now	O
distribute	O
binaries	O
as	O
AppImages	B-Application
.	O
</s>
