<s>
CBL-Mariner	B-Application
(	O
in	O
which	O
CBL	O
stands	O
for	O
Common	O
Base	O
Linux	B-Operating_System
)	O
is	O
a	O
free	B-License
and	I-License
open-source	I-License
Linux	B-Application
distribution	I-Application
that	O
Microsoft	O
has	O
developed	O
.	O
</s>
<s>
It	O
is	O
the	O
base	O
container	B-General_Concept
OS	O
for	O
Microsoft	B-Application
Azure	I-Application
services	O
and	O
the	O
graphical	O
component	O
of	O
WSL	O
2	O
.	O
</s>
<s>
CBL-Mariner	B-Application
is	O
being	O
developed	O
by	O
the	O
Linux	B-Operating_System
Systems	O
Group	O
at	O
Microsoft	O
for	O
its	O
edge	O
network	O
services	O
and	O
as	O
part	O
of	O
its	O
cloud	O
infrastructure	O
.	O
</s>
<s>
The	O
company	O
uses	O
it	O
as	O
the	O
base	O
Linux	B-Operating_System
for	O
containers	O
in	O
the	O
Azure	B-Application
Stack	I-Application
HCI	B-Architecture
implementation	O
of	O
Azure	O
Kubernetes	B-General_Concept
Service	O
.	O
</s>
<s>
Microsoft	O
also	O
uses	O
CBL-Mariner	B-Application
in	O
Azure	O
IoT	O
Edge	O
to	O
run	O
Linux	B-Operating_System
workloads	O
on	O
Windows	B-Operating_System
IoT	I-Operating_System
,	O
and	O
as	O
a	O
backend	O
distro	O
to	O
host	O
the	O
Weston	B-Application
compositor	O
for	O
WSLg	O
.	O
</s>
<s>
In	O
a	O
similar	O
approach	O
to	O
Fedora	O
CoreOS	O
,	O
CBL-Mariner	B-Application
only	O
has	O
the	O
basic	O
packages	B-Application
needed	O
to	O
support	O
and	O
run	O
containers	O
.	O
</s>
<s>
Common	O
Linux	B-Operating_System
tools	O
are	O
used	O
to	O
add	O
packages	B-Application
and	O
manage	O
security	O
updates	O
.	O
</s>
<s>
Updates	O
are	O
offered	O
either	O
as	O
RPM	B-Application
packages	I-Application
or	O
as	O
complete	O
disk	B-Application
images	I-Application
that	O
can	O
be	O
deployed	O
as	O
needed	O
.	O
</s>
<s>
Using	O
RPM	B-Application
allows	O
adding	O
custom	O
packages	B-Application
to	O
a	O
base	O
CBL-Mariner	B-Application
image	O
to	O
support	O
additional	O
features	O
and	O
services	O
as	O
needed	O
.	O
</s>
<s>
Notable	O
features	O
include	O
an	O
iptables-based	O
firewall	B-Application
,	O
support	O
for	O
signed	O
updates	O
,	O
and	O
a	O
hardened	O
kernel	B-Operating_System
.	O
</s>
<s>
Its	O
source	O
code	O
is	O
available	O
on	O
GitHub	B-Application
,	O
mainly	O
under	O
the	B-License
MIT	I-License
License	I-License
,	O
with	O
some	O
components	O
under	O
Photon	O
License	O
,	O
Apache	B-Application
License	I-Application
v2	I-Application
,	O
GPLv2	O
,	O
and	O
LGPLv2.1	B-Application
.	O
</s>
<s>
Building	O
CBL-Mariner	B-Application
requires	O
the	O
Go	B-Application
programming	I-Application
language	I-Application
,	O
QEMU	B-Application
utilities	O
,	O
and	O
RPM	B-Application
.	O
</s>
