<s>
nghttp2	B-Language
is	O
a	O
C	B-Language
library	B-Library
.	O
</s>
<s>
It	O
is	O
an	O
implementation	O
of	O
HTTP/2	B-Protocol
.	O
</s>
<s>
nghttp2	B-Language
was	O
created	O
by	O
Tatsuhiro	O
Tsujikawa	O
as	O
a	O
derivative	O
of	O
spdylay	O
,	O
an	O
implementation	O
of	O
SPDY	B-Protocol
,	O
a	O
communications	O
protocol	O
created	O
by	O
Google	B-Application
in	O
2009	O
,	O
in	O
C	B-Language
.	O
</s>
<s>
Several	O
well-known	O
projects	O
use	O
nghttp2	B-Language
to	O
implement	O
HTTP/2	B-Protocol
,	O
including	O
Apache	B-Application
and	O
cURL	B-Language
.	O
</s>
<s>
nghttp2	B-Language
will	O
send	O
a	O
WINDOW_UPDATE	O
frame	O
upon	O
consuming	O
more	O
than	O
half	O
of	O
the	O
flow	O
control	O
window	O
.	O
</s>
<s>
For	O
instance	O
,	O
if	O
the	O
sender	O
specifies	O
the	O
SETTINGS_INITAL_WINDOW_SIZE	O
as	O
65,535	O
octets	O
in	O
the	O
SETTINGS	O
frame	O
,	O
nghttp2	B-Language
will	O
send	O
a	O
WINDOW_UPDATE	O
frame	O
upon	O
exceeding	O
32,768	O
octets	O
.	O
</s>
<s>
nghttp2	B-Language
offers	O
multiple	O
tools	O
.	O
</s>
<s>
nghttp	O
is	O
a	O
command-line	O
tool	O
that	O
uses	O
nghttp2	B-Language
to	O
output	O
HTTP/2	B-Protocol
messages	O
from	O
a	O
URL	O
.	O
</s>
<s>
nghttp	O
's	O
dependency-based	O
priority	O
is	O
based	O
on	O
Firefox	B-Application
;	O
when	O
a	O
connection	O
is	O
established	O
,	O
nghttp	O
sends	O
five	O
PRIORITY	O
frames	O
.	O
</s>
<s>
Other	O
tools	O
provided	O
include	O
nghttpd	O
,	O
an	O
HTTP/2	B-Protocol
server	O
,	O
nghttpx	O
,	O
an	O
HTTP/2	B-Protocol
proxy	O
,	O
h2load	O
,	O
an	O
HTTP/2	B-Protocol
load	O
testing	O
tool	O
,	O
and	O
inflatehd	O
and	O
deflatehd	O
,	O
tools	O
to	O
decompress	O
and	O
compress	O
using	O
the	O
HPACK	B-Protocol
header	O
compression	O
algorithm	O
.	O
</s>
<s>
nghttp3	O
is	O
an	O
implementation	O
of	O
HTTP/3	B-Protocol
in	O
C	B-Language
and	O
authored	O
by	O
Tsujikawa	O
.	O
</s>
<s>
nghttp3	O
uses	O
the	O
QUIC	B-Protocol
network	O
protocol	O
designed	O
by	O
Jim	O
Roskind	O
at	O
Google	B-Application
.	I-Application
</s>
