<s>
FoundationDB	B-Operating_System
is	O
a	O
free	B-License
and	I-License
open-source	I-License
multi-model	B-Operating_System
distributed	B-Operating_System
NoSQL	B-General_Concept
database	O
developed	O
by	O
Apple	O
Inc	O
.	O
with	O
a	O
shared-nothing	B-Operating_System
architecture	I-Operating_System
.	O
</s>
<s>
The	O
core	O
database	O
exposes	O
an	O
ordered	O
key	B-Data_Structure
–	I-Data_Structure
value	I-Data_Structure
store	I-Data_Structure
with	O
transactions	B-General_Concept
.	O
</s>
<s>
The	O
transactions	B-General_Concept
are	O
able	O
to	O
read	O
or	O
write	O
multiple	O
keys	O
stored	O
on	O
any	O
machine	O
in	O
the	O
cluster	O
while	O
fully	O
supporting	O
ACID	O
properties	O
.	O
</s>
<s>
Transactions	B-General_Concept
are	O
used	O
to	O
implement	O
a	O
variety	O
of	O
data	B-Operating_System
models	I-Operating_System
via	O
layers	O
.	O
</s>
<s>
The	O
FoundationDB	B-Operating_System
Alpha	O
program	O
began	O
in	O
January	O
2012	O
and	O
concluded	O
on	O
March	O
4	O
,	O
2013	O
with	O
their	O
public	O
Beta	O
release	O
.	O
</s>
<s>
A	O
notice	O
on	O
the	O
FoundationDB	B-Operating_System
web	O
site	O
indicated	O
that	O
the	O
company	O
has	O
"	O
evolved	O
"	O
its	O
mission	O
and	O
would	O
no	O
longer	O
offer	O
downloads	O
of	O
the	O
software	O
.	O
</s>
<s>
On	O
April	O
19	O
,	O
2018	O
,	O
Apple	O
open	O
sourced	O
the	O
software	O
,	O
releasing	O
it	O
under	O
the	O
Apache	B-Application
2.0	I-Application
license	I-Application
.	O
</s>
<s>
The	O
main	O
features	O
of	O
FoundationDB	B-Operating_System
included	O
the	O
following	O
:	O
</s>
<s>
Transaction	O
processing	O
employs	O
multiversion	B-Operating_System
concurrency	I-Operating_System
control	I-Operating_System
for	O
reads	O
and	O
optimistic	B-Operating_System
concurrency	I-Operating_System
for	O
writes	O
.	O
</s>
<s>
Transactions	B-General_Concept
can	O
span	O
multiple	O
keys	O
stored	O
on	O
multiple	O
machines	O
.	O
</s>
<s>
FoundationDB	B-Operating_System
guarantees	O
serializable	B-Operating_System
isolation	B-General_Concept
and	O
strong	O
durability	B-General_Concept
via	O
redundant	O
storage	O
on	O
disk	O
before	O
transactions	B-General_Concept
are	O
considered	O
committed	B-Language
.	O
</s>
<s>
Layers	O
map	O
new	O
data	B-Operating_System
models	I-Operating_System
,	O
APIs	O
,	O
and	O
query	O
languages	O
to	O
the	O
FoundationDB	B-Operating_System
core	O
.	O
</s>
<s>
They	O
employ	O
FoundationDB	B-Operating_System
's	O
ability	O
to	O
update	O
multiple	O
data	O
elements	O
in	O
a	O
single	O
transaction	O
,	O
ensuring	O
consistency	O
.	O
</s>
<s>
An	O
example	O
is	O
their	O
SQL	B-Language
layer	O
.	O
</s>
<s>
FoundationDB	B-Operating_System
is	O
designed	O
for	O
deployment	O
on	O
distributed	B-Operating_System
clusters	O
of	O
commodity	B-Device
hardware	I-Device
running	O
Linux	B-Application
.	O
</s>
<s>
FoundationDB	B-Operating_System
stores	O
each	O
piece	O
of	O
data	O
on	O
multiple	O
machines	O
according	O
to	O
a	O
configurable	O
replication	O
factor	O
.	O
</s>
<s>
FoundationDB	B-Operating_System
is	O
designed	O
to	O
support	O
horizontal	O
scaling	O
though	O
the	O
addition	O
of	O
machines	O
to	O
a	O
cluster	O
while	O
automatically	O
handling	O
data	O
replication	O
and	O
partitioning	O
.	O
</s>
<s>
FoundationDB	B-Operating_System
supports	O
packages	O
for	O
Linux	B-Application
,	O
Windows	B-Application
,	O
and	O
macOS	B-Application
.	O
</s>
<s>
The	O
Linux	B-Application
version	O
supports	O
production	O
clusters	O
,	O
while	O
the	O
Windows	B-Application
and	O
macOS	B-Application
versions	O
support	O
local	O
operation	O
for	O
development	O
purposes	O
.	O
</s>
<s>
Configurations	O
on	O
Amazon	B-General_Concept
EC2	I-General_Concept
are	O
also	O
supported	O
.	O
</s>
<s>
FoundationDB	B-Operating_System
supports	O
language	O
bindings	O
for	O
Python	O
,	O
Go	O
,	O
Ruby	O
,	O
Node.js	O
,	O
Java	O
,	O
PHP	O
,	O
and	O
C	B-Language
,	O
all	O
of	O
which	O
are	O
made	O
available	O
with	O
the	O
product	O
.	O
</s>
<s>
The	O
design	O
of	O
FoundationDB	B-Operating_System
results	O
in	O
several	O
limitations	O
:	O
</s>
<s>
FoundationDB	B-Operating_System
does	O
not	O
support	O
transactions	B-General_Concept
running	O
over	O
five	O
seconds	O
.	O
</s>
<s>
FoundationDB	B-Operating_System
,	O
headquartered	O
in	O
Vienna	O
,	O
VA	O
,	O
was	O
started	O
in	O
2009	O
by	O
Nick	O
Lavezzo	O
,	O
Dave	O
Rosenthal	O
,	O
and	O
Dave	O
Scherer	O
,	O
drawing	O
on	O
their	O
experience	O
in	O
executive	O
and	O
technology	O
roles	O
at	O
their	O
previous	O
company	O
,	O
Visual	O
Sciences	O
.	O
</s>
<s>
In	O
March	O
2015	O
the	O
FoundationDB	B-Operating_System
Community	O
site	O
was	O
updated	O
to	O
state	O
that	O
the	O
company	O
had	O
changed	O
directions	O
and	O
would	O
no	O
longer	O
be	O
offering	O
downloads	O
of	O
its	O
product	O
.	O
</s>
<s>
On	O
April	O
19	O
,	O
2018	O
,	O
Apple	O
open	O
sourced	O
the	O
software	O
,	O
releasing	O
it	O
under	O
the	O
Apache	B-Application
2.0	I-Application
license	I-Application
.	O
</s>
