<s>
iPXE	B-Device
is	O
an	O
open-source	B-Application
implementation	O
of	O
the	O
Preboot	B-Device
eXecution	I-Device
Environment	I-Device
(	O
PXE	B-Device
)	O
client	O
software	O
and	O
bootloader	B-Application
,	O
created	O
in	O
2010	O
as	O
a	O
fork	B-Application
of	O
gPXE	B-Device
(	O
gPXE	B-Device
was	O
named	O
Etherboot	B-Device
until	O
2008	O
)	O
.	O
</s>
<s>
It	O
can	O
be	O
used	O
to	O
enable	O
computers	O
without	O
built-in	O
PXE	B-Device
capability	O
to	O
boot	O
from	O
the	O
network	O
,	O
or	O
to	O
provide	O
additional	O
features	O
beyond	O
what	O
built-in	O
PXE	B-Device
provides	O
.	O
</s>
<s>
While	O
standard	O
PXE	B-Device
clients	O
use	O
only	O
TFTP	B-Device
to	O
load	O
parameters	O
and	O
programs	O
from	O
the	O
server	O
,	O
iPXE	B-Device
client	O
software	O
can	O
use	O
additional	O
protocols	O
,	O
including	O
HTTP	B-Protocol
,	O
iSCSI	B-Protocol
,	O
ATA	B-Protocol
over	I-Protocol
Ethernet	I-Protocol
(	O
AoE	O
)	O
,	O
and	O
Fibre	B-Protocol
Channel	I-Protocol
over	I-Protocol
Ethernet	I-Protocol
(	O
FCoE	B-Protocol
)	O
.	O
</s>
<s>
Also	O
,	O
on	O
certain	O
hardware	O
,	O
iPXE	B-Device
client	O
software	O
can	O
use	O
a	O
Wi-Fi	O
link	O
,	O
as	O
opposed	O
to	O
the	O
wired	O
connection	O
required	O
by	O
the	O
PXE	B-Device
standard	O
.	O
</s>
<s>
The	O
iPXE	B-Device
client	O
is	O
a	O
superset	O
of	O
,	O
and	O
can	O
replace	O
or	O
supplement	O
,	O
prior	O
PXE	B-Device
implementations	O
.	O
</s>
<s>
iPXE	B-Device
is	O
the	O
official	O
replacement	O
for	O
gPXE	B-Device
.	O
</s>
<s>
it	O
has	O
every	O
feature	O
of	O
gPXE	B-Device
,	O
and	O
users	O
can	O
seamlessly	O
upgrade	O
from	O
gPXE	B-Device
to	O
iPXE	B-Device
.	O
</s>
<s>
iPXE	B-Device
can	O
be	O
booted	O
by	O
a	O
computer	O
either	O
by	O
replacing	O
(	O
re-flashing	O
)	O
the	O
existing	O
standard	O
PXE	B-Device
ROM	B-Device
on	O
a	O
supported	O
network	B-Protocol
interface	I-Protocol
card	I-Protocol
(	O
NIC	O
)	O
,	O
or	O
by	O
booting	O
the	O
NIC	O
's	O
standard	O
PXE	B-Device
ROM	B-Device
and	O
then	O
chainloading	B-Operating_System
into	O
the	O
iPXE	B-Device
binary	O
,	O
thus	O
obtaining	O
its	O
features	O
without	O
the	O
need	O
to	O
re-flash	O
a	O
NIC	O
.	O
</s>
<s>
iPXE	B-Device
firmware	O
embeds	O
its	O
configuration	O
script	O
into	O
the	O
firmware	O
image	O
,	O
thus	O
any	O
changes	O
to	O
the	O
configuration	O
require	O
a	O
NIC	O
to	O
be	O
re-flashed	O
.	O
</s>
<s>
iPXE	B-Device
implements	O
its	O
own	O
PXE	B-Device
stack	O
either	O
by	O
using	O
the	O
network	B-Protocol
card	I-Protocol
driver	O
provided	O
by	O
iPXE	B-Device
,	O
or	O
the	O
standard	O
PXE	B-Device
UNDI	B-Device
driver	O
if	O
iPXE	B-Device
is	O
chainloaded	O
from	O
a	O
standard	O
PXE	B-Device
ROM	B-Device
.	O
</s>
<s>
Implementing	O
an	O
independent	O
PXE	B-Device
stack	O
allows	O
clients	O
without	O
the	O
standard	O
PXE	B-Device
ROM	B-Device
on	O
their	O
NICs	O
to	O
use	O
an	O
alternative	O
iPXE	B-Device
stack	O
by	O
loading	O
it	O
from	O
an	O
alternative	O
medium	O
.	O
</s>
<s>
Although	O
its	O
basic	O
role	O
was	O
to	O
implement	O
a	O
PXE	B-Device
stack	O
,	O
iPXE	B-Device
can	O
be	O
also	O
used	O
as	O
a	O
network	O
boot	B-Application
manager	I-Application
with	O
limited	O
capabilities	O
for	O
menu-based	O
interaction	O
with	O
end	O
users	O
.	O
</s>
<s>
iPXE	B-Device
can	O
fetch	O
boot	O
files	O
using	O
multiple	O
network	O
protocols	O
,	O
such	O
as	O
TFTP	B-Device
,	O
NFS	B-Protocol
,	O
HTTP	B-Protocol
or	O
FTP	B-Protocol
.	O
</s>
<s>
iPXE	B-Device
can	O
act	O
as	O
a	O
boot	B-Application
loader	I-Application
for	O
the	O
Linux	B-Application
kernel	O
,	O
with	O
support	O
for	O
multiboot	O
.	O
</s>
<s>
For	O
other	O
operating	O
systems	O
,	O
for	O
example	O
Windows	B-Operating_System
CE	I-Operating_System
,	O
iPXE	B-Device
chain-loads	B-Operating_System
corresponding	O
Microsoft	O
boot	B-Application
loader	I-Application
.	O
</s>
<s>
Additionally	O
,	O
iPXE	B-Device
is	O
scriptable	O
and	O
can	O
load	O
COMBOOT	O
and	O
COM32	O
SYSLINUX	B-Application
extensions	O
,	O
which	O
,	O
for	O
example	O
,	O
allows	O
SYSLINUX-based	O
graphical	O
menu	O
capabilities	O
to	O
be	O
available	O
for	O
network	O
booting	O
.	O
</s>
