<s>
Vaadin	B-Language
(	O
)	O
is	O
an	O
open-source	B-Application
web	B-Application
application	I-Application
development	I-Application
platform	O
for	O
Java	B-Language
.	O
</s>
<s>
Vaadin	B-Language
includes	O
a	O
set	O
of	O
Web	B-Language
Components	I-Language
,	O
a	O
Java	B-Language
web	B-Application
framework	I-Application
,	O
and	O
a	O
set	O
of	O
tools	O
that	O
enable	O
developers	O
to	O
implement	O
modern	O
web	O
graphical	B-Application
user	I-Application
interfaces	I-Application
(	O
GUI	B-Application
)	O
using	O
the	O
Java	B-Language
programming	I-Language
language	I-Language
only	O
(	O
instead	O
of	O
HTML	O
and	O
JavaScript	B-Language
)	O
,	O
TypeScript	B-Language
only	O
,	O
or	O
a	O
combination	O
of	O
both	O
.	O
</s>
<s>
Development	O
was	O
first	O
started	O
as	O
an	O
adapter	O
on	O
top	O
of	O
the	O
Millstone	O
3	O
open-source	B-Application
web	B-Application
framework	I-Application
released	O
in	O
the	O
year	O
2002	O
.	O
</s>
<s>
It	O
introduced	O
an	O
Ajax-based	O
client	O
communication	O
and	O
rendering	O
engine	O
.	O
</s>
<s>
As	O
a	O
consequence	O
of	O
this	O
,	O
a	O
large	O
part	O
of	O
Vaadin	B-Language
's	O
server-side	B-Application
API	B-Application
is	O
still	O
compatible	O
with	O
Millstone	O
's	O
Swing-like	B-Language
APIs	B-Application
.	O
</s>
<s>
In	O
early	O
2007	O
the	O
product	O
name	O
was	O
changed	O
to	O
IT	B-Language
Mill	I-Language
Toolkit	I-Language
and	O
version	O
4	O
was	O
released	O
.	O
</s>
<s>
It	O
used	O
a	O
proprietary	O
JavaScript	B-Language
Ajax-implementation	O
for	O
the	O
client-side	O
rendering	O
,	O
which	O
made	O
it	O
rather	O
complicated	O
to	O
implement	O
new	O
widgets	O
.	O
</s>
<s>
By	O
the	O
end	O
of	O
the	O
year	O
2007	O
the	O
proprietary	O
client-side	O
implementation	O
was	O
abandoned	O
and	O
GWT	B-Language
was	O
integrated	O
on	O
top	O
of	O
the	O
server-side	B-Application
components	O
.	O
</s>
<s>
At	O
the	O
same	O
time	O
,	O
the	O
product	O
license	O
was	O
changed	O
to	O
the	O
open	O
source	O
Apache	B-Application
License	I-Application
2.0	I-Application
.	O
</s>
<s>
The	O
first	O
production-ready	O
release	O
of	O
IT	B-Language
Mill	I-Language
Toolkit	I-Language
5	O
was	O
made	O
on	O
March	O
4	O
,	O
2009	O
,	O
after	O
an	O
over	O
one	O
year	O
beta	O
period	O
.	O
</s>
<s>
On	O
September	O
11	O
,	O
2008	O
,	O
it	O
was	O
publicly	O
announced	O
that	O
Michael	O
Widenius	O
–	O
the	O
main	O
author	O
of	O
the	O
original	O
version	O
of	O
MySQL	B-Application
–	O
invested	O
in	O
IT	O
Mill	O
,	O
the	O
developer	O
of	O
Vaadin	B-Language
.	O
</s>
<s>
On	O
May	O
20	O
,	O
2009	O
,	O
IT	B-Language
Mill	I-Language
Toolkit	I-Language
changed	O
its	O
name	O
to	O
Vaadin	B-Language
Framework	O
.	O
</s>
<s>
Later	O
,	O
IT	O
Mill	O
Ltd	O
,	O
the	O
company	O
behind	O
the	O
open	O
source	O
Vaadin	B-Language
Framework	O
,	O
changed	O
its	O
name	O
to	O
Vaadin	B-Language
Ltd	O
.	O
</s>
<s>
On	O
March	O
30	O
,	O
2010	O
,	O
Vaadin	B-Language
Directory	O
was	O
opened	O
.	O
</s>
<s>
It	O
added	O
a	O
channel	O
for	O
distributing	O
add-on	O
components	O
to	O
the	O
core	O
Vaadin	B-Language
Framework	O
,	O
both	O
for	O
free	O
or	O
commercially	O
.	O
</s>
<s>
+Release	O
historyLTS	O
VersionRelease	O
dateNotes	O
and	O
new	O
features	O
since	O
the	O
previous	O
LTS	O
version	O
launch620	O
May	O
2009Initial	O
release73	O
February	O
2013821	O
February	O
2017Improvements	O
include	O
a	O
re-written	O
data	O
binding	O
API	B-Application
that	O
uses	O
modern	O
Java	B-Language
features	O
such	O
as	O
type	O
parameters	O
and	O
lambda	O
expressions	O
,	O
and	O
more	O
efficient	O
memory	O
and	O
CPU	O
usage.1025	O
June	O
2018It	O
's	O
possible	O
to	O
use	O
Vaadin	B-Language
's	O
UI	O
components	O
from	O
any	O
technology	O
compatible	O
with	O
Web	B-Language
Components	I-Language
.	O
</s>
<s>
Vaadin	B-Language
Directory	O
adds	O
Web	B-Language
Components	I-Language
distribution	O
.	O
</s>
<s>
Vaadin	B-Language
Flow	O
—	O
the	O
next	O
generation	O
of	O
Vaadin	B-Language
Framework	O
—	O
was	O
presented	O
as	O
a	O
server-side	B-Application
Java	B-Language
web	B-Application
framework	I-Application
on	O
top	O
of	O
Vaadin	B-Language
's	O
UI	O
components.1414	O
August	O
2019New	O
UI	O
components	O
,	O
CDI	O
and	O
OSGi	B-Application
support	O
,	O
Gradle	B-Language
integration	O
,	O
dynamic	O
registration	O
of	O
routes	O
,	O
keyboard	O
shortcuts	O
API	B-Application
,	O
support	O
for	O
npm	B-Language
and	O
Bower.231	O
March	O
2022New	O
release	O
model	O
.	O
</s>
<s>
New	O
UI	O
components	O
,	O
reworked	O
design	O
system	O
,	O
feature	O
flags	O
,	O
npm	B-Language
is	O
now	O
the	O
default	O
package	O
manager	O
.	O
</s>
<s>
Vaadin	B-Language
Flow	O
(	O
formerly	O
Vaadin	B-Language
Framework	O
)	O
is	O
a	O
Java	B-Language
web	B-Application
framework	I-Application
for	O
building	O
web	B-Application
applications	I-Application
and	O
websites	O
.	O
</s>
<s>
Vaadin	B-Language
Flow	O
's	O
programming	O
model	O
allows	O
developers	O
to	O
use	O
Java	B-Language
as	O
the	O
programming	O
language	O
for	O
implementing	O
User	O
Interfaces	O
(	O
UIs	O
)	O
without	O
having	O
to	O
directly	O
use	O
HTML	O
or	O
JavaScript	B-Language
.	O
</s>
<s>
Vaadin	B-Language
Flow	O
features	O
a	O
server-side	B-Application
architecture	O
which	O
means	O
that	O
most	O
of	O
the	O
UI	O
logic	O
runs	O
securely	O
on	O
the	O
server	O
reducing	O
the	O
exposure	O
to	O
attackers	O
.	O
</s>
<s>
On	O
the	O
client-side	O
,	O
Vaadin	B-Language
Flow	O
is	O
built	O
on	O
top	O
of	O
Web	O
Component	O
standards	O
.	O
</s>
<s>
The	O
client/server	O
communication	O
is	O
automatically	O
handled	O
through	O
WebSocket	B-Protocol
or	O
HTTP	B-Protocol
with	O
light	O
JSON	B-General_Concept
messages	O
that	O
update	O
both	O
,	O
the	O
UI	O
in	O
the	O
browser	O
and	O
the	O
UI	O
state	O
in	O
the	O
server	O
.	O
</s>
<s>
Vaadin	B-Language
Flow	O
's	O
Java	B-Language
API	B-Application
includes	O
classes	O
such	O
as	O
TextField	O
,	O
Button	O
,	O
ComboBox	O
,	O
Grid	O
,	O
and	O
many	O
others	O
that	O
can	O
be	O
configured	O
,	O
styled	O
,	O
and	O
added	O
into	O
layout	O
objects	O
instances	O
of	O
classes	O
such	O
as	O
VerticalLayout	O
,	O
HorizontalLayout	O
,	O
SplitLayout	O
,	O
and	O
others	O
.	O
</s>
<s>
Views	O
are	O
created	O
by	O
custom	O
Java	B-Language
classes	O
that	O
implement	O
another	O
UI	O
component	O
(	O
custom	O
or	O
provided	O
by	O
the	O
framework	O
)	O
.	O
</s>
<s>
Hilla	O
(	O
formerly	O
Vaadin	B-Language
Fusion	O
)	O
is	O
a	O
web	B-Application
framework	I-Application
that	O
integrates	O
Spring	O
Boot	O
Java	B-Language
backends	O
with	O
reactive	O
front	O
ends	O
implemented	O
in	O
TypeScript	B-Language
.	O
</s>
<s>
This	O
combination	O
offers	O
a	O
fully	O
type-safe	O
development	O
platform	O
by	O
combining	O
server-side	B-Application
business	O
logic	O
in	O
Java	B-Language
and	O
type-safety	O
in	O
the	O
client	O
side	O
with	O
the	O
TypeScript	B-Language
programming	O
language	O
.	O
</s>
<s>
Views	O
are	O
implemented	O
using	O
Lit	O
—	O
a	O
lightweight	O
library	O
for	O
creating	O
Web	B-Language
Components	I-Language
.	O
</s>
<s>
Vaadin	B-Language
includes	O
a	O
set	O
of	O
User	O
Interface	O
(	O
UI	O
)	O
components	O
implemented	O
as	O
Web	B-Language
Components	I-Language
.	O
</s>
<s>
These	O
components	O
include	O
a	O
server-side	B-Application
Java	B-Language
API	B-Application
(	O
Vaadin	B-Language
Flow	O
)	O
but	O
can	O
also	O
be	O
used	O
directly	O
in	O
HTML	O
documents	O
as	O
well	O
.	O
</s>
<s>
Vaadin	B-Language
's	O
UI	O
components	O
work	O
with	O
mouse	O
and	O
touch	O
events	O
,	O
can	O
be	O
customized	O
with	O
CSS	O
,	O
are	O
compatible	O
with	O
WAI-ARIA	B-General_Concept
,	O
include	O
keyboard	O
and	O
screen	O
readers	O
support	O
,	O
and	O
support	O
right-to-left	O
languages	O
.	O
</s>
<s>
The	O
following	O
table	O
shows	O
a	O
list	O
of	O
the	O
UI	O
components	O
included	O
in	O
Vaadin	B-Language
:	O
</s>
<s>
Vaadin	B-Language
offers	O
two	O
certification	O
tracks	O
to	O
prove	O
that	O
a	O
developer	O
is	O
proficient	O
with	O
Vaadin	B-Language
Flow	O
:	O
</s>
