<s>
Realm	O
is	O
an	O
open	B-License
source	I-License
object	B-Application
database	I-Application
management	I-Application
system	I-Application
,	O
initially	O
for	O
mobile	O
operating	O
systems	O
(	O
Android/iOS	O
)	O
but	O
also	O
available	O
for	O
platforms	O
such	O
as	O
Xamarin	B-Application
,	O
React	B-Application
Native	I-Application
,	O
and	O
others	O
,	O
including	O
desktop	O
applications	O
(	O
Windows	B-Application
)	O
.	O
</s>
<s>
It	O
is	O
licensed	O
under	O
the	O
Apache	B-Application
License	I-Application
.	O
</s>
<s>
It	O
allows	O
two-way	O
synchronization	O
between	O
the	O
Realm	O
Object	O
Server	O
and	O
the	O
client	O
side	O
databases	B-Application
that	O
belong	O
to	O
the	O
given	O
logged-in	O
user	O
.	O
</s>
<s>
Both	O
a	O
developer	O
and	O
a	O
commercial	O
edition	O
was	O
released	O
,	O
along	O
with	O
a	O
business	O
license	O
for	O
integrating	O
with	O
other	O
database	B-Application
management	I-Application
systems	I-Application
such	O
as	O
PostgreSQL	B-Application
.	O
</s>
<s>
In	O
spring	O
2019	O
,	O
MongoDB	B-Application
acquired	O
Realm	O
for	O
39	O
million	O
USD	O
.	O
</s>
<s>
It	O
was	O
promoted	O
as	O
NoSQL	B-General_Concept
with	O
configurable	O
durability	O
,	O
and	O
the	O
ability	O
to	O
share	O
the	O
same	O
groups	O
of	O
data	O
across	O
multiple	O
processes	O
,	O
but	O
also	O
even	O
multiple	O
devices	O
and	O
clusters	O
.	O
</s>
<s>
Realm	O
announced	O
version	O
1.0	O
in	O
June	O
2016	O
,	O
and	O
released	O
a	O
platform	O
for	O
real-time	O
two-way	O
synchronization	O
(	O
beta	O
in	O
2016	O
September	O
,	O
release	O
in	O
2017	O
January	O
)	O
,	O
and	O
provided	O
a	O
Node.js	B-Language
SDK	B-Application
for	O
server-side	O
applications	O
.	O
</s>
<s>
In	O
May	O
2017	O
,	O
UWP	B-Device
support	O
was	O
announced	O
.	O
</s>
<s>
As	O
Realm	O
is	O
an	O
object	O
store	O
,	O
its	O
typed	O
language-specific	O
APIs	B-General_Concept
map	O
typed	O
objects	O
directly	O
into	O
the	O
Realm	O
file	O
–	O
therefore	O
classes	O
are	O
used	O
as	O
the	O
schema	O
definition	O
.	O
</s>
<s>
The	O
query	O
results	O
returned	O
by	O
Realm	O
are	O
thread-local	O
views	O
to	O
the	O
current	O
"	O
database	O
version	O
"	O
(	O
as	O
Realm	O
handles	O
concurrency	O
with	O
MVCC	B-Operating_System
architecture	I-Operating_System
)	O
,	O
and	O
these	O
views	O
"	O
automatically	O
update	O
"	O
when	O
a	O
transaction	O
is	O
committed	O
from	O
any	O
thread	O
,	O
as	O
long	O
as	O
Realm	O
is	O
able	O
to	O
update	O
its	O
instance	O
version	O
(	O
which	O
is	O
possible	O
on	O
threads	O
that	O
are	O
able	O
to	O
receive	O
change	O
notifications	O
)	O
.	O
</s>
