<s>
WebScaleSQL	B-Application
was	O
an	O
open-source	B-Application
relational	B-Application
database	I-Application
management	I-Application
system	I-Application
(	O
RDBMS	B-Application
)	O
created	O
as	O
a	O
software	B-General_Concept
branch	I-General_Concept
of	O
the	O
production-ready	O
community	O
releases	O
of	O
MySQL	B-Application
.	O
</s>
<s>
By	O
joining	O
efforts	O
of	O
a	O
few	O
companies	O
and	O
incorporating	O
various	O
changes	O
and	O
new	O
features	O
into	O
MySQL	B-Application
,	O
WebScaleSQL	B-Application
aimed	O
toward	O
fulfilling	O
various	O
needs	O
arising	O
from	O
the	O
deployment	O
of	O
MySQL	B-Application
in	O
large-scale	O
environments	O
,	O
which	O
involve	O
large	O
amounts	O
of	O
data	O
and	O
numerous	O
database	B-Application
servers	I-Application
.	O
</s>
<s>
The	O
source	O
code	O
of	O
WebScaleSQL	B-Application
is	O
hosted	O
on	O
GitHub	B-Application
and	O
licensed	O
under	O
the	O
terms	O
of	O
version2	O
of	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
.	O
</s>
<s>
Running	O
MySQL	B-Application
on	O
numerous	O
servers	B-Application
with	O
large	O
amounts	O
of	O
data	O
,	O
at	O
the	O
scale	O
of	O
terabytes	O
and	O
petabytes	O
of	O
data	O
,	O
creates	O
a	O
set	O
of	O
difficulties	O
that	O
in	O
many	O
cases	O
arise	O
the	O
need	O
for	O
implementing	O
specific	O
customized	O
MySQL	B-Application
features	O
,	O
or	O
the	O
need	O
for	O
introducing	O
functional	O
changes	O
to	O
MySQL	B-Application
.	O
</s>
<s>
WebScaleSQL	B-Application
was	O
announced	O
on	O
March	O
27	O
,	O
2014	O
as	O
a	O
joint	O
effort	O
of	O
Facebook	B-Application
,	O
Google	B-Application
,	O
LinkedIn	B-Application
and	O
Twitter	B-Application
(	O
with	O
Alibaba	O
Group	O
joining	O
in	O
January	O
2015	O
)	O
,	O
aiming	O
to	O
provide	O
a	O
centralized	O
development	O
structure	O
for	O
extending	O
MySQL	B-Application
with	O
new	O
features	O
specific	O
to	O
its	O
large-scale	O
deployments	O
,	O
such	O
as	O
building	O
large	O
replicated	B-General_Concept
databases	I-General_Concept
running	O
on	O
server	B-Operating_System
farms	I-Operating_System
.	O
</s>
<s>
As	O
a	O
result	O
,	O
WebScaleSQL	B-Application
attempted	O
to	O
open	O
a	O
path	O
toward	O
deduplicating	O
the	O
efforts	O
each	O
founding	O
company	O
had	O
been	O
putting	O
into	O
maintaining	O
its	O
own	O
branch	B-General_Concept
of	O
MySQL	B-Application
,	O
and	O
toward	O
bringing	O
together	O
more	O
developers	O
.	O
</s>
<s>
WebScaleSQL	B-Application
was	O
created	O
as	O
a	O
branch	B-General_Concept
of	O
the	O
MySQL	B-Application
's	O
latest	O
production-ready	O
community	O
release	O
,	O
which	O
was	O
version	O
5.6	O
.	O
</s>
<s>
As	O
the	O
project	O
aimed	O
to	O
tightly	O
follow	O
new	O
MySQL	B-Application
community	O
releases	O
,	O
a	O
branching	B-General_Concept
path	O
was	O
selected	O
instead	O
of	O
becoming	O
a	O
software	B-Application
fork	I-Application
of	O
MySQL	B-Application
.	O
</s>
<s>
The	O
selection	O
of	O
MySQL	B-Application
production-ready	O
community	O
releases	O
for	O
the	O
WebScaleSQL	B-Application
's	O
upstream	B-General_Concept
,	O
instead	O
of	O
selecting	O
some	O
of	O
the	O
available	O
MySQL	B-Application
forks	B-Application
was	O
the	O
result	O
of	O
a	O
consensus	O
between	O
the	O
four	O
founding	O
companies	O
,	O
which	O
concluded	O
that	O
the	O
features	O
already	O
existing	O
in	O
MySQL5.6	O
are	O
suitable	O
for	O
large-scale	O
deployments	O
,	O
while	O
additional	O
features	O
of	O
the	O
same	O
kind	O
are	O
planned	O
for	O
MySQL5.7	O
.	O
</s>
<s>
The	O
initial	O
changes	O
and	O
feature	O
additions	O
that	O
WebScaleSQL	B-Application
introduced	O
to	O
the	O
MySQL5.6	O
codebase	B-General_Concept
came	O
from	O
the	O
engineers	O
employed	O
by	O
the	O
four	O
founding	O
companies	O
;	O
however	O
,	O
the	O
project	O
was	O
open	O
to	O
peer-reviewed	O
community	O
contributions	O
.	O
</s>
<s>
WebScaleSQL	B-Application
is	O
distributed	O
in	O
a	O
source-code-only	O
form	O
,	O
with	O
no	O
official	O
binaries	O
available	O
.	O
</s>
<s>
,	O
compiling	B-Language
the	O
source	O
code	O
and	O
running	O
WebScaleSQL	B-Application
is	O
supported	O
only	O
on	O
x86-64	B-Device
Linux	B-Application
hosts	O
,	O
requiring	O
at	O
the	O
same	O
time	O
a	O
toolchain	B-General_Concept
that	O
supports	O
C99	B-Language
and	O
C++11	B-Language
language	O
standards	O
.	O
</s>
<s>
The	O
source	O
code	O
is	O
hosted	O
on	O
GitHub	B-Application
and	O
available	O
under	O
version2	O
of	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
(	O
GPL	B-License
v2	O
)	O
.	O
</s>
<s>
In	O
December	O
2016	O
,	O
the	O
WebScaleSQL	B-Application
website	O
announced	O
the	O
companies	O
originally	O
involved	O
in	O
collaborating	O
on	O
the	O
project	O
(	O
Facebook	B-Application
,	O
Google	B-Application
,	O
LinkedIn	B-Application
,	O
Twitter	B-Application
,	O
and	O
Alibaba	O
)	O
would	O
no	O
longer	O
contribute	O
to	O
the	O
project	O
.	O
</s>
