<s>
H2O	B-Language
is	O
a	O
free	B-License
and	I-License
open-source	I-License
web	B-Application
server	I-Application
software	O
.	O
</s>
<s>
It	O
is	O
written	O
in	O
C	B-Language
,	O
and	O
is	O
distributed	O
under	O
the	O
terms	O
of	O
the	B-License
MIT	I-License
License	I-License
.	O
</s>
<s>
It	O
is	O
designed	O
on	O
the	O
presence	O
of	O
HTTP/2	B-Protocol
and	O
TLS	B-Protocol
,	O
and	O
maximizing	O
the	O
use	O
of	O
HTTP/2	B-Protocol
technologies	O
such	O
as	O
prioritization	O
and	O
server	B-Protocol
push	I-Protocol
,	O
it	O
achieves	O
significantly	O
better	O
performance	O
than	O
conventional	O
web	B-Application
server	I-Application
software	O
such	O
as	O
nginx	B-Operating_System
.	O
</s>
<s>
H2O	B-Language
has	O
the	O
following	O
key	O
features	O
:	O
</s>
<s>
In	O
,	O
started	O
the	O
development	O
H2O	B-Language
as	O
a	O
mobile	B-Application
game	I-Application
server	O
inside	O
DeNA	O
.	O
</s>
<s>
The	O
initial	O
version	O
was	O
released	O
in	O
,	O
and	O
the	O
first	O
stable	O
version	O
was	O
released	O
in	O
when	O
the	O
HTTP/2	B-Protocol
specification	O
was	O
finalized	O
.	O
</s>
