<s>
Ninja	B-Application
is	O
a	O
small	O
build	B-Application
system	I-Application
developed	O
by	O
Evan	O
Martin	O
,	O
a	O
Google	B-Application
employee	O
.	O
</s>
<s>
Ninja	B-Application
has	O
a	O
focus	O
on	O
speed	O
and	O
it	O
differs	O
from	O
other	O
build	B-Application
systems	I-Application
in	O
two	O
major	O
respects	O
:	O
it	O
is	O
designed	O
to	O
have	O
its	O
input	O
files	O
generated	O
by	O
a	O
higher-level	O
build	B-Application
system	I-Application
,	O
and	O
it	O
is	O
designed	O
to	O
run	O
builds	O
as	O
fast	O
as	O
possible	O
.	O
</s>
<s>
In	O
essence	O
,	O
Ninja	B-Application
is	O
meant	O
to	O
replace	O
Make	B-Application
,	O
which	O
is	O
slow	O
when	O
performing	O
incremental	O
(	O
or	O
no-op	O
)	O
builds	O
.	O
</s>
<s>
This	O
can	O
considerably	O
slow	O
down	O
developers	O
working	O
on	O
large	O
projects	O
,	O
such	O
as	O
Google	B-Application
Chrome	I-Application
which	O
compiles	O
40,000	O
input	O
files	O
into	O
a	O
single	O
executable	O
.	O
</s>
<s>
In	O
fact	O
,	O
Google	B-Application
Chrome	I-Application
is	O
a	O
main	O
user	O
and	O
motivation	O
for	O
Ninja	B-Application
.	O
</s>
<s>
It	O
's	O
also	O
used	O
to	O
build	O
Android	O
(	O
via	O
Makefile	O
translation	O
by	O
Kati	O
)	O
,	O
and	O
is	O
used	O
by	O
most	O
developers	O
working	O
on	O
LLVM	B-Application
.	O
</s>
<s>
In	O
contrast	O
to	O
Make	B-Application
,	O
Ninja	B-Application
lacks	O
features	O
such	O
as	O
string	O
manipulation	O
,	O
as	O
Ninja	B-Application
build	O
files	O
are	O
not	O
meant	O
to	O
be	O
written	O
by	O
hand	O
.	O
</s>
<s>
Instead	O
,	O
a	O
"	O
build	O
generator	O
"	O
should	O
be	O
used	O
to	O
generate	O
Ninja	B-Application
build	O
files	O
.	O
</s>
<s>
Gyp	B-Operating_System
,	O
CMake	B-Language
,	O
Meson	B-Application
,	O
and	O
gn	O
are	O
popular	O
build	O
management	O
software	B-Application
tools	I-Application
which	O
support	O
creating	O
build	O
files	O
for	O
Ninja	B-Application
.	O
</s>
