<s>
Darling	B-Language
is	O
a	O
free	B-License
and	I-License
open-source	I-License
macOS	B-Application
compatibility	B-General_Concept
layer	I-General_Concept
for	O
Linux	B-Application
.	O
</s>
<s>
It	O
duplicates	O
functions	O
of	O
macOS	B-Application
by	O
providing	O
alternative	O
implementations	O
of	O
the	O
libraries	O
and	O
frameworks	O
that	O
macOS	B-Application
programs	O
call	O
.	O
</s>
<s>
This	O
method	O
of	O
duplication	O
differs	O
from	O
other	O
methods	O
that	O
might	O
also	O
be	O
considered	O
emulation	O
,	O
where	O
macOS	B-Application
programs	O
run	O
in	O
a	O
virtual	B-Architecture
machine	I-Architecture
.	O
</s>
<s>
Darling	B-Language
has	O
been	O
called	O
the	O
counterpart	O
to	O
WINE	B-Application
for	O
running	O
macOS	B-Application
apps	O
.	O
</s>
<s>
The	O
layer	O
has	O
been	O
shown	O
to	O
work	O
with	O
many	O
console	B-Device
apps	I-Device
,	O
such	O
as	O
Midnight	B-Protocol
Commander	I-Protocol
,	O
The	B-Application
Unarchiver	I-Application
,	O
Python	B-Language
,	O
etc	O
.	O
</s>
<s>
on	O
the	O
layer	O
,	O
but	O
it	O
also	O
has	O
basic	O
support	O
for	O
graphical	O
applications	O
based	O
on	O
the	O
Cocoa	B-Operating_System
framework	O
.	O
</s>
<s>
Darling	B-Language
has	O
the	O
ability	O
to	O
extract	O
Apple	B-Operating_System
Disk	I-Operating_System
Images	I-Operating_System
.	O
</s>
<s>
The	O
project	O
aims	O
to	O
support	O
iOS	B-Application
applications	O
in	O
the	O
future	O
.	O
</s>
<s>
At	O
the	O
entry	O
of	O
the	O
Darling	B-Language
system	O
is	O
a	O
loader	O
for	O
Mach-O	B-Operating_System
binaries	O
,	O
the	O
executable	O
format	O
for	O
Apple	O
's	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
Darling	B-Language
's	O
predecessor	O
,	O
maloader	O
,	O
presented	O
a	O
maximalist	O
approach	O
to	O
the	O
problem	O
by	O
trying	O
to	O
replicate	O
everything	O
that	O
Apple	O
's	O
dynamic	B-Application
library	I-Application
loader	O
dyld	B-Application
does	O
.	O
</s>
<s>
This	O
proved	O
to	O
be	O
hard	O
,	O
and	O
since	O
a	O
2017	O
"	O
Mach-O	B-Operating_System
transition	O
"	O
Darling	B-Language
has	O
been	O
using	O
a	O
lightweight	O
loader	O
just	O
enough	O
to	O
launch	O
the	O
open-source	O
Apple	O
dyld	B-Application
instead	O
.	O
</s>
<s>
To	O
provide	O
the	O
macOS	B-Application
binaries	O
with	O
a	O
kernel	B-Operating_System
,	O
Darling	B-Language
uses	O
a	O
modified	O
XNU	B-Operating_System
kernel	I-Operating_System
wrapped	O
into	O
a	O
Linux	B-Application
kernel	I-Application
module	I-Application
.	O
</s>
<s>
This	O
module	B-Application
handles	O
the	O
typical	O
job	O
of	O
a	O
Mach	B-Operating_System
kernel	I-Operating_System
,	O
mainly	O
Ports	O
IPC	B-Operating_System
handling	O
.	O
</s>
<s>
Some	O
licensing	O
issues	O
exist	O
in	O
the	O
darling-mach	O
module	B-Application
,	O
as	O
the	O
team	O
are	O
adding	O
GNU	B-License
GPL	I-License
modifications	O
to	O
the	O
APSL	B-License
kernel	B-Operating_System
.	O
</s>
<s>
Higher	O
than	O
the	O
kernel	B-Operating_System
is	O
the	O
root	O
environment	O
.	O
</s>
<s>
Darling	B-Language
,	O
like	O
WINE	B-Application
,	O
supports	O
chroot	B-Application
prefixes	O
,	O
implemented	O
using	O
the	O
Linux	B-Application
overlayfs	B-Application
(	O
as	O
opposed	O
to	O
path	O
translation	O
in	O
WINE	B-Application
)	O
.	O
</s>
<s>
PID	B-Operating_System
,	O
IPC	B-Operating_System
,	O
and	O
UTS	O
namespaces	O
are	O
used	O
to	O
create	O
a	O
container	B-Application
for	O
the	O
Darwin	O
system	O
inside	O
.	O
</s>
<s>
The	O
frameworks	O
and	O
system	O
libraries	O
in	O
Darling	B-Language
are	O
,	O
to	O
the	O
best	O
possible	O
extent	O
,	O
based	O
on	O
source	O
code	O
released	O
by	O
Apple	O
.	O
</s>
<s>
The	O
Mach-O	B-Operating_System
transition	O
allows	O
these	O
frameworks	O
to	O
be	O
built	O
more	O
easily	O
,	O
because	O
they	O
are	O
now	O
built	O
as	O
the	O
Mach-O	B-Operating_System
format	O
they	O
were	O
intended	O
for	O
.	O
</s>
<s>
To	O
fill	O
in	O
the	O
gaps	O
for	O
many	O
higher-level	O
frameworks	O
like	O
Cocoa	B-Operating_System
,	O
Darling	B-Language
uses	O
code	O
from	O
Cocotron	O
,	O
ApportableFoundation	O
,	O
and	O
GNUstep	B-Application
.	O
</s>
<s>
The	O
larger	O
Darling	B-Language
system	O
is	O
based	O
on	O
many	O
components	O
which	O
use	O
various	O
licenses	O
,	O
all	O
of	O
which	O
are	O
open-source	O
.	O
</s>
<s>
The	O
primary	O
license	O
is	O
GPLv3	B-License
.	O
</s>
