<s>
Source	B-Operating_System
2	I-Operating_System
is	O
a	O
video	O
game	O
engine	O
developed	O
by	O
Valve	O
.	O
</s>
<s>
The	O
engine	O
was	O
announced	O
in	O
2015	O
as	O
the	O
successor	O
to	O
the	O
original	O
Source	B-Application
engine	I-Application
,	O
with	O
the	O
first	O
game	O
to	O
use	O
it	O
,	O
Dota	B-Application
2	I-Application
,	O
being	O
ported	O
from	O
Source	B-Application
that	O
same	O
year	O
.	O
</s>
<s>
Since	O
then	O
,	O
Valve	O
's	O
Artifact	B-Application
,	O
Dota	B-Application
Underlords	I-Application
,	O
Half-Life	B-Application
:	I-Application
Alyx	I-Application
,	O
Aperture	B-Application
Desk	I-Application
Job	I-Application
and	O
Counter-Strike	O
2	O
have	O
all	O
been	O
made	O
with	O
the	O
engine	O
.	O
</s>
<s>
Plans	O
for	O
a	O
successor	O
to	O
the	O
original	O
Source	B-Application
engine	I-Application
began	O
following	O
the	O
release	O
of	O
Half-Life	B-Application
2	I-Application
:	I-Application
Episode	I-Application
Two	I-Application
in	O
2007	O
.	O
</s>
<s>
The	O
first	O
engine	O
tech	O
demo	O
was	O
created	O
in	O
2010	O
by	O
remaking	O
a	O
map	O
from	O
Left	B-Application
4	I-Application
Dead	I-Application
2	I-Application
.	O
</s>
<s>
At	O
the	O
2014	O
Game	O
Developers	O
Conference	O
,	O
Valve	O
employee	O
Sergiy	O
Migdalskiy	O
showed	O
off	O
a	O
Source	B-Operating_System
2	I-Operating_System
physics	O
debugging	O
tool	O
being	O
used	O
in	O
Left	B-Application
4	I-Application
Dead	I-Application
2	I-Application
.	O
</s>
<s>
Source	B-Operating_System
2	I-Operating_System
was	O
first	O
made	O
available	O
via	O
Steam	B-Application
Workshop	O
tools	O
for	O
Dota	B-Application
2	I-Application
in	O
2014	O
prior	O
to	O
it	O
being	O
officially	O
announced	O
at	O
the	O
2015	O
Game	O
Developers	O
Conference	O
.	O
</s>
<s>
Valve	O
also	O
stated	O
that	O
it	O
would	O
support	O
the	O
Vulkan	B-Application
graphics	I-Application
API	I-Application
and	O
use	O
a	O
new	O
in-house	O
physics	O
engine	O
called	O
Rubikon	O
,	O
which	O
would	O
replace	O
the	O
need	O
for	O
the	O
third-party	O
Havok	B-General_Concept
tools	O
.	O
</s>
<s>
Gabe	O
Newell	O
,	O
president	O
and	O
founder	O
of	O
Valve	O
,	O
said	O
that	O
the	O
company	O
were	O
prioritizing	O
the	O
development	O
of	O
their	O
own	O
games	O
before	O
they	O
would	O
release	O
the	O
engine	O
and	O
its	O
software	B-Application
development	I-Application
kit	I-Application
to	O
the	O
public	O
as	O
a	O
means	O
of	O
ensuring	O
the	O
highest	O
quality	O
for	O
developers	O
;	O
adding	O
that	O
they	O
were	O
intending	O
to	O
make	O
the	O
engine	O
free	O
to	O
use	O
for	O
game	O
developers	O
as	O
long	O
as	O
the	O
game	O
is	O
published	O
on	O
their	O
Steam	B-Application
service	I-Application
.	O
</s>
<s>
In	O
June	O
2015	O
,	O
Valve	O
announced	O
that	O
the	O
entirety	O
of	O
Dota	B-Application
2	I-Application
would	O
be	O
ported	O
over	O
to	O
Source	B-Operating_System
2	I-Operating_System
in	O
an	O
update	O
called	O
Dota	B-Application
2	I-Application
Reborn	O
.	O
</s>
<s>
Source	B-Operating_System
2	I-Operating_System
has	O
also	O
been	O
used	O
for	O
Valve	O
's	O
Artifact	B-Application
and	O
Dota	B-Application
Underlords	I-Application
,	O
with	O
the	O
engine	O
later	O
being	O
supported	O
on	O
Android	B-Application
and	O
iOS	B-Application
for	O
the	O
latter	O
.	O
</s>
<s>
The	O
engine	O
also	O
supports	O
the	O
creation	O
of	O
games	O
in	O
virtual	B-Application
reality	I-Application
,	O
being	O
used	O
in	O
SteamVR	O
Home	O
,	O
the	O
Robot	O
Repair	O
tech	O
demo	O
within	O
The	B-Application
Lab	I-Application
,	O
and	O
Half-Life	B-Application
:	I-Application
Alyx	I-Application
.	O
</s>
<s>
Source	B-Operating_System
2	I-Operating_System
tools	O
made	O
specifically	O
for	O
creating	O
content	O
for	O
Half-Life	B-Application
:	I-Application
Alyx	I-Application
were	O
released	O
in	O
May	O
2020	O
.	O
</s>
