<s>
Mozilla	B-Language
Firefox	I-Language
3.5	I-Language
is	O
a	O
version	O
of	O
the	O
Firefox	B-Application
web	I-Application
browser	I-Application
released	O
in	O
June	O
2009	O
,	O
adding	O
a	O
variety	O
of	O
new	O
features	O
to	O
Firefox	B-Application
.	O
</s>
<s>
Version	O
3.5	O
was	O
touted	O
as	O
being	O
twice	O
as	O
fast	O
as	O
3.0	O
(	O
due	O
its	O
TraceMonkey	O
JavaScript	B-Language
engine	O
and	O
rendering	O
improvements	O
)	O
.	O
</s>
<s>
It	O
includes	O
private	B-Protocol
browsing	I-Protocol
,	O
has	O
tear-off	O
tabs	O
,	O
and	O
uses	O
the	O
Gecko	O
1.9.1	O
engine	O
.	O
</s>
<s>
It	O
was	O
codenamed	O
Shiretoko	O
during	O
development	O
,	O
and	O
was	O
initially	O
numbered	O
Firefox	B-Language
3.1	I-Language
before	O
Mozilla	O
developers	O
decided	O
to	O
change	O
the	O
version	O
to	O
3.5	O
,	O
to	O
reflect	O
the	O
inclusion	O
of	O
a	O
significantly	O
greater	O
scope	O
of	O
changes	O
than	O
were	O
originally	O
planned	O
.	O
</s>
<s>
It	O
is	O
the	O
last	O
major	O
version	O
to	O
support	O
X	B-Device
BitMap	I-Device
images	O
.	O
</s>
<s>
Estimates	O
of	O
Firefox	B-Language
3.5	I-Language
'	O
s	O
global	O
market	O
share	O
in	O
February	O
2010	O
were	O
around	O
15	O
–	O
20%	O
and	O
rose	O
rapidly	O
in	O
July	O
2009	O
as	O
users	O
migrated	O
from	O
Firefox	B-Language
3.0	I-Language
.	O
</s>
<s>
From	O
January	O
2010	O
it	O
began	O
to	O
decline	O
as	O
users	O
migrated	O
to	O
Firefox	B-Protocol
3.6	I-Protocol
.	O
</s>
<s>
Between	O
mid-December	O
2009	O
and	O
February	O
2010	O
,	O
Firefox	B-Language
3.5	I-Language
was	O
the	O
most	O
popular	O
browser	B-Application
(	O
when	O
counting	O
individual	O
browser	B-Application
versions	O
)	O
according	O
to	O
StatCounter	O
,	O
and	O
was	O
one	O
of	O
the	O
top	O
3	O
browser	B-Application
versions	O
according	O
to	O
Net	O
Applications	O
.	O
</s>
<s>
Both	O
milestones	O
involved	O
passing	O
Internet	B-Application
Explorer	I-Application
7	I-Application
,	O
which	O
previously	O
held	O
the	O
No	O
.	O
</s>
<s>
Due	O
to	O
the	O
January	O
2010	O
,	O
well-publicized	O
vulnerability	O
in	O
Microsoft	O
's	O
Internet	O
Explorer	O
browser	B-Application
,	O
the	O
German	O
,	O
French	O
,	O
and	O
Australian	O
governments	O
had	O
publicly	O
issued	O
warnings	O
to	O
Internet	O
Explorer	O
users	O
to	O
use	O
alternative	O
browsers	B-Application
,	O
at	O
least	O
until	O
a	O
fix	O
for	O
the	O
security	O
hole	O
was	O
made	O
.	O
</s>
<s>
The	O
first	O
browser	B-Application
they	O
recommended	O
was	O
Mozilla	B-Application
Firefox	I-Application
,	O
followed	O
by	O
Google	B-Application
Chrome	I-Application
.	O
</s>
<s>
Even	O
before	O
the	O
release	O
of	O
Firefox	B-Language
3.0	I-Language
on	O
June	O
17	O
,	O
2008	O
,	O
Firefox	B-Language
3.1	I-Language
was	O
in	O
development	O
under	O
the	O
codename	O
"	O
Shiretoko	O
"	O
.	O
</s>
<s>
It	O
was	O
planned	O
to	O
include	O
new	O
interface	O
features	O
such	O
as	O
tab	O
previews	O
,	O
tag	O
auto-completion	O
,	O
HTML	B-Application
5	I-Application
tag	O
support	O
,	O
and	O
CSS	B-Language
text	O
shadows	O
.	O
</s>
<s>
The	O
Gecko	B-Language
engine	I-Language
was	O
updated	O
to	O
include	O
CSS3	O
features	O
and	O
includes	O
the	O
HTML	O
Canvas	O
text	O
API	O
.	O
</s>
<s>
The	O
Alpha	O
release	O
showed	O
an	O
18%	O
improvement	O
in	O
the	O
Acid3	O
test	O
over	O
Firefox	B-Language
3.0	I-Language
,	O
scoring	O
84/100	O
.	O
</s>
<s>
Version	O
3.1	O
Alpha	O
2	O
was	O
launched	O
on	O
September	O
5	O
,	O
2008	O
,	O
implementing	O
the	O
HTML	B-Application
5	I-Application
video	O
element	O
support	O
and	O
preliminary	O
support	O
for	O
web	O
worker	O
thread	O
,	O
enhancing	O
the	O
speed	O
of	O
some	O
JavaScript	B-Language
computations	O
.	O
</s>
<s>
On	O
October	O
14	O
,	O
2008	O
,	O
the	O
first	O
beta	O
of	O
Firefox	B-Language
3.1	I-Language
was	O
released	O
.	O
</s>
<s>
It	O
included	O
a	O
new	O
TraceMonkey	O
JavaScript	B-Language
engine	O
,	O
which	O
is	O
not	O
enabled	O
by	O
default	O
,	O
and	O
the	O
implementation	O
of	O
the	O
W3C	B-Language
Geolocation	I-Language
API	I-Language
.	O
</s>
<s>
Beta	O
2	O
was	O
released	O
on	O
December	O
8	O
,	O
2008	O
and	O
included	O
a	O
new	O
private	B-Protocol
browsing	I-Protocol
feature	O
.	O
</s>
<s>
Firefox	B-Language
3.1	I-Language
Beta	O
3	O
was	O
released	O
on	O
March	O
12	O
,	O
2009	O
,	O
followed	O
by	O
Beta	O
4	O
,	O
the	O
first	O
to	O
be	O
labeled	O
as	O
version	O
3.5	O
,	O
on	O
April	O
27	O
,	O
2009	O
.	O
</s>
<s>
On	O
June	O
8	O
,	O
2009	O
,	O
Mozilla	O
released	O
Firefox	B-Language
3.5	I-Language
Preview	O
(	O
labeled	O
3.5b99	O
)	O
in	O
order	O
to	O
receive	O
additional	O
testing	O
before	O
it	O
became	O
the	O
release	O
candidate	O
.	O
</s>
<s>
Release	O
Candidate	O
1	O
was	O
released	O
as	O
an	O
update	O
to	O
Firefox	B-Language
3.5	I-Language
Preview	O
users	O
on	O
June	O
17	O
,	O
2009	O
.	O
</s>
<s>
Firefox	B-Language
3.5	I-Language
was	O
officially	O
released	O
on	O
June	O
30	O
,	O
2009	O
.	O
</s>
<s>
Firefox	B-Language
3.5	I-Language
uses	O
the	O
Gecko	O
1.9.1	O
engine	O
,	O
which	O
adds	O
features	O
that	O
were	O
not	O
included	O
in	O
the	O
3.0	O
release	O
.	O
</s>
<s>
These	O
include	O
support	O
for	O
the	O
<video> and <audio>	O
elements	O
defined	O
in	O
the	O
HTML	B-Application
5	I-Application
draft	O
specification	O
,	O
including	O
native	O
support	O
for	O
Ogg	B-Algorithm
Theora	I-Algorithm
encoded	O
video	O
and	O
Vorbis	B-Algorithm
encoded	O
audio	O
.	O
</s>
<s>
Other	O
features	O
new	O
in	O
Firefox	B-Language
3.5	I-Language
include	O
a	O
private	B-Protocol
browsing	I-Protocol
mode	O
,	O
native	O
support	O
for	O
JSON	B-General_Concept
and	O
web	O
worker	O
threads	O
,	O
and	O
many	O
other	O
new	O
web	O
technologies	O
.	O
</s>
<s>
Multi-touch	B-Application
support	O
was	O
also	O
added	O
to	O
the	O
release	O
,	O
including	O
gesture	O
support	O
like	O
pinching	O
for	O
zooming	O
and	O
swiping	O
for	O
back	O
and	O
forward	O
.	O
</s>
<s>
Firefox	B-Language
3.5	I-Language
also	O
features	O
an	O
updated	O
logo	O
from	O
the	O
previous	O
releases	O
.	O
</s>
<s>
A	O
minor	O
change	O
for	O
Version	O
3.5	O
is	O
the	O
default	O
search	O
engine	O
in	O
Russian	O
language	O
builds	O
,	O
which	O
uses	O
the	O
search	O
engine	O
Yandex	O
rather	O
than	O
Google	B-Application
,	O
after	O
a	O
survey	O
of	O
Russian	O
Firefox	B-Application
users	O
indicated	O
they	O
preferred	O
Yandex	O
.	O
</s>
<s>
Starting	O
July	O
14	O
,	O
2009	O
,	O
the	O
upgrade	O
to	O
3.5	O
was	O
offered	O
to	O
users	O
of	O
Firefox	B-Language
3.0	I-Language
through	O
the	O
automatic	O
internal	O
"	O
push	B-General_Concept
"	O
update	O
mechanism	O
.	O
</s>
<s>
With	O
the	O
release	O
of	O
Firefox	B-Protocol
3.6.18	I-Protocol
,	O
Mozilla	O
issued	O
an	O
update	O
to	O
move	O
remaining	O
Firefox	B-Language
3.5	I-Language
users	O
to	O
the	O
new	O
browser	B-Application
,	O
finally	O
ending	O
support	O
for	O
3.5	O
.	O
</s>
