<s>
Watir	B-Application
(	O
Web	B-Application
Application	I-Application
Testing	O
in	O
Ruby	B-Language
,	O
pronounced	O
water	O
)	O
,	O
is	O
an	O
open-source	O
family	O
of	O
Ruby	B-Language
libraries	O
for	O
automating	O
web	O
browsers	O
.	O
</s>
<s>
It	O
drives	O
Internet	B-Application
Explorer	I-Application
,	O
Firefox	B-Application
,	O
Chrome	B-Application
,	O
Opera	B-Application
and	O
Safari	B-Application
,	O
and	O
is	O
available	O
as	O
a	O
RubyGems	B-Application
gem	B-Application
.	O
</s>
<s>
Watir	B-Application
was	O
primarily	O
developed	O
by	O
Bret	O
Pettichord	O
and	O
Paul	O
Rogers	O
.	O
</s>
<s>
Watir	B-Application
project	O
consists	O
of	O
several	O
smaller	O
projects	O
.	O
</s>
<s>
The	O
most	O
important	O
ones	O
are	O
watir-classic	O
,	O
watir-webdriver	O
and	O
watirspec	O
.	O
</s>
<s>
Watir-classic	O
makes	O
use	O
of	O
the	O
fact	O
that	O
Ruby	B-Language
has	O
built	O
in	O
Object	B-Operating_System
Linking	I-Operating_System
and	I-Operating_System
Embedding	I-Operating_System
(	O
OLE	O
)	O
capabilities	O
.	O
</s>
<s>
As	O
such	O
it	O
is	O
possible	O
to	O
drive	O
Internet	B-Application
Explorer	I-Application
programmatically	O
.	O
</s>
<s>
Watir-classic	O
operates	O
differently	O
than	O
HTTP	O
based	O
test	B-Application
tools	I-Application
,	O
which	O
operate	O
by	O
simulating	O
a	O
browser	O
.	O
</s>
<s>
Instead	O
Watir-classic	O
directly	O
drives	O
the	O
browser	O
through	O
the	O
OLE	O
protocol	O
,	O
which	O
is	O
implemented	O
over	O
the	O
Component	B-Application
Object	I-Application
Model	I-Application
(	O
COM	O
)	O
architecture	O
.	O
</s>
<s>
The	O
COM	O
permits	O
interprocess	O
communication	O
(	O
such	O
as	O
between	O
Ruby	B-Language
and	O
Internet	B-Application
Explorer	I-Application
)	O
and	O
dynamic	O
object	O
creation	O
and	O
manipulation	O
(	O
which	O
is	O
what	O
the	O
Ruby	B-Language
program	O
does	O
to	O
the	O
Internet	B-Application
Explorer	I-Application
)	O
.	O
</s>
<s>
Technically	O
,	O
the	O
Internet	B-Application
Explorer	I-Application
process	O
is	O
the	O
server	O
and	O
serves	O
the	O
automation	O
objects	O
,	O
exposing	O
their	O
methods	O
;	O
while	O
the	O
Ruby	B-Language
program	O
then	O
becomes	O
the	O
client	O
which	O
manipulates	O
the	O
automation	O
objects	O
.	O
</s>
<s>
Watir-webdriver	O
is	O
a	O
modern	O
version	O
of	O
the	O
Watir	B-Application
API	O
based	O
on	O
Selenium	B-Library
.	O
</s>
<s>
Selenium	B-Library
2.0	O
(	O
selenium-webdriver	O
)	O
aims	O
to	O
be	O
the	O
reference	O
implementation	O
of	O
the	O
WebDriver	O
specification	O
.	O
</s>
<s>
In	O
Ruby	B-Language
,	O
Jari	O
Bakken	O
has	O
implemented	O
the	O
Watir	B-Application
API	O
as	O
a	O
wrapper	O
around	O
the	O
Selenium	B-Library
2.0	O
API	O
.	O
</s>
<s>
Not	O
only	O
is	O
Watir-webdriver	O
derived	O
from	O
Selenium	B-Library
2.0	O
,	O
it	O
is	O
also	O
built	O
from	O
the	O
HTML	B-Language
specification	O
,	O
so	O
Watir-webdriver	O
should	O
always	O
be	O
compatible	O
with	O
existing	O
W3C	O
specifications	O
.	O
</s>
<s>
Watirspec	O
is	O
executable	O
specification	O
of	O
the	O
Watir	B-Application
API	O
,	O
like	O
RubySpec	B-Language
is	O
for	O
Ruby	B-Language
.	O
</s>
