<s>
Sumatra	B-Language
PDF	I-Language
is	O
a	O
free	B-License
and	I-License
open-source	I-License
document	B-Application
viewer	I-Application
that	O
supports	O
many	O
document	O
formats	O
including	O
:	O
Portable	B-Application
Document	I-Application
Format	I-Application
(	O
PDF	B-Application
)	O
,	O
Microsoft	B-Protocol
Compiled	I-Protocol
HTML	I-Protocol
Help	I-Protocol
(	O
CHM	O
)	O
,	O
DjVu	O
,	O
EPUB	O
,	O
FictionBook	O
(	O
FB2	O
)	O
,	O
MOBI	O
,	O
PRC	B-Application
,	O
Open	B-Device
XML	I-Device
Paper	I-Device
Specification	I-Device
(	O
OpenXPS	B-Device
,	O
OXPS	O
,	O
XPS	B-Application
)	O
,	O
and	O
Comic	O
Book	O
Archive	O
file	O
(	O
CB7	O
,	O
CBR	O
,	O
CBT	O
,	O
CBZ	O
)	O
.	O
</s>
<s>
If	O
Ghostscript	B-Language
is	O
installed	O
,	O
it	O
supports	O
PostScript	B-Language
files	O
.	O
</s>
<s>
It	O
is	O
developed	O
exclusively	O
for	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
For	O
rendering	O
PDFs	B-Application
,	O
it	O
uses	O
the	O
MuPDF	B-Language
library	O
.	O
</s>
<s>
Sumatra	O
was	O
designed	O
for	O
portable	B-Application
use	O
,	O
as	O
it	O
consists	O
of	O
one	O
file	O
with	O
no	O
external	O
dependencies	O
,	O
making	O
it	O
usable	O
from	O
an	O
external	O
USB	O
drive	O
,	O
needing	O
no	O
installation	O
.	O
</s>
<s>
This	O
classifies	O
it	O
as	O
a	O
portable	B-Application
application	I-Application
to	O
read	O
PDF	B-Application
,	O
XPS	B-Application
,	O
DjVu	O
,	O
CHM	O
,	O
eBooks	O
(	O
ePub	O
and	O
Mobi	O
)	O
and	O
Comic	O
Book	O
(	O
CBZ	O
and	O
CBR	O
)	O
formats	O
.	O
</s>
<s>
As	O
is	O
characteristic	O
of	O
many	O
portable	B-Application
applications	I-Application
,	O
Sumatra	O
uses	O
little	O
disk	O
space	O
.	O
</s>
<s>
In	O
2009	O
,	O
Sumatra	O
1.0	O
had	O
a	O
1.21	O
MB	O
setup	O
file	O
,	O
compared	O
to	O
Adobe	B-Application
Reader	I-Application
9.5	O
'	O
s	O
32	O
MB	O
.	O
</s>
<s>
In	O
January	O
,	O
2017	O
,	O
the	O
latest	O
version	O
of	O
SumatraPDF	B-Language
,	O
3.1.2	O
,	O
had	O
a	O
single	O
6.1	O
Mb	O
executable	O
file	O
;	O
in	O
comparison	O
,	O
Adobe	B-Application
Reader	I-Application
XI	O
used	O
320	O
MB	O
of	O
disk	O
space	O
.	O
</s>
<s>
The	O
PDF	B-Application
format	I-Application
's	O
use	O
restrictions	O
were	O
implemented	O
in	O
Sumatra	O
0.6	O
,	O
preventing	O
users	O
from	O
printing	O
or	O
copying	O
from	O
documents	O
that	O
the	O
document	O
author	O
restricts	O
,	O
a	O
form	O
of	O
Digital	O
Rights	O
Management	O
.	O
</s>
<s>
Kowalczyk	O
stated	O
"	O
I	O
decided	O
that	O
 [ Sumatra ] 	O
will	O
honor	O
PDF	B-Application
creator	O
's	O
wishes	O
"	O
.	O
</s>
<s>
Other	O
open-source	B-Application
readers	O
like	O
Okular	B-Language
and	O
Evince	B-Language
make	O
this	O
optional	O
,	O
and	O
Debian	O
patches	O
software	O
to	O
remove	O
these	O
restrictions	O
,	O
in	O
accord	O
with	O
its	O
principles	O
of	O
interoperability	O
and	O
re-use	O
.	O
</s>
<s>
Through	O
version	O
1.1	O
,	O
printing	O
was	O
achieved	O
by	O
rasterizing	O
each	O
PDF	B-Application
page	O
to	O
a	O
bitmap	O
.	O
</s>
<s>
Since	O
version	O
0.9.1	O
,	O
hyperlinks	O
embedded	O
in	O
PDF	B-Application
documents	I-Application
have	O
been	O
supported	O
.	O
</s>
<s>
Sumatra	O
supports	O
SyncTeX	O
,	O
a	O
bidirectional	O
method	O
to	O
synchronize	O
TeX	B-Application
source	O
and	O
PDF	B-Application
output	O
produced	O
by	O
pdfTeX	B-Language
or	O
XeTeX	B-Application
.	O
</s>
<s>
Sumatra	B-Language
PDF	I-Language
is	O
written	O
mainly	O
by	O
two	O
contributors	O
:	O
Krzysztof	O
Kowalczyk	O
and	O
Simon	O
Bünzli	O
.	O
</s>
<s>
The	O
source	O
code	O
is	O
developed	O
in	O
two	O
programming	O
languages	O
,	O
mostly	O
in	O
C++	B-Language
,	O
with	O
some	O
components	O
in	O
C	B-Language
.	O
The	O
source	O
code	O
is	O
provided	O
with	O
support	O
for	O
Microsoft	B-Application
Visual	I-Application
Studio	I-Application
.	O
</s>
<s>
As	O
it	O
was	O
first	O
designed	O
when	O
Windows	B-Application
XP	I-Application
was	O
the	O
current	O
version	O
of	O
Windows	O
,	O
Sumatra	O
initially	O
had	O
some	O
incompatibilities	O
with	O
earlier	O
versions	O
of	O
Windows	O
.	O
</s>
<s>
Support	O
for	O
Windows	B-Application
95	I-Application
,	O
98	B-Device
and	O
ME	B-Device
has	O
since	O
been	O
removed	O
.	O
</s>
<s>
Initially	O
,	O
Kowalczyk	O
did	O
not	O
release	O
a	O
64-bit	B-Device
version	O
of	O
Sumatra	O
,	O
indicating	O
that	O
while	O
it	O
might	O
offer	O
slightly	O
more	O
speed	O
and	O
available	O
memory	O
,	O
he	O
believed	O
at	O
that	O
time	O
that	O
it	O
would	O
greatly	O
add	O
to	O
user	O
confusion	O
and	O
that	O
the	O
benefits	O
would	O
not	O
outweigh	O
the	O
potential	O
costs	O
.	O
</s>
<s>
However	O
,	O
some	O
users	O
requested	O
64-bit	B-Device
builds	O
of	O
Sumatra	O
and	O
other	O
developers	O
had	O
compiled	O
unofficial	O
64-bit	B-Device
builds	O
which	O
loaded	O
documents	O
faster	O
than	O
the	O
32-bit	O
builds	O
.	O
</s>
<s>
In	O
October	O
2015	O
,	O
an	O
official	O
64-bit	B-Device
version	O
of	O
Sumatra	O
was	O
released	O
.	O
</s>
<s>
The	O
Sumatra	O
source	O
code	O
was	O
originally	O
hosted	O
on	O
Google	B-Protocol
Code	I-Protocol
.	O
</s>
<s>
The	O
source	O
code	O
is	O
currently	O
hosted	O
on	O
GitHub	B-Application
.	O
</s>
<s>
The	O
first	O
version	O
of	O
Sumatra	B-Language
PDF	I-Language
,	O
designated	O
version	O
0.1	O
,	O
was	O
based	O
on	O
Xpdf	B-Protocol
0.2	O
and	O
was	O
released	O
on	O
1	O
June	O
2006	O
.	O
</s>
<s>
It	O
switched	O
to	O
Poppler	B-Language
from	O
version	O
0.2	O
.	O
</s>
<s>
In	O
version	O
0.4	O
,	O
it	O
changed	O
to	O
MuPDF	B-Language
for	O
more	O
speed	O
and	O
better	O
support	O
for	O
the	O
Windows	O
platform	O
.	O
</s>
<s>
Poppler	B-Language
remained	O
as	O
alternative	O
engine	O
for	O
a	O
time	O
,	O
and	O
from	O
version	O
0.6	O
to	O
0.8	O
it	O
was	O
automatically	O
used	O
to	O
render	O
pages	O
that	O
MuPDF	B-Language
failed	O
to	O
load	O
.	O
</s>
<s>
Poppler	B-Language
was	O
removed	O
in	O
version	O
0.9	O
,	O
released	O
on	O
10	O
August	O
2008	O
.	O
</s>
<s>
In	O
July	O
2009	O
,	O
Sumatra	B-Language
PDF	I-Language
changed	O
its	O
license	O
from	O
GNU	O
GPLv2	O
to	O
GNU	O
GPLv3	O
to	O
match	O
the	O
same	O
license	O
change	O
on	O
MuPDF	B-Language
.	O
</s>
<s>
In	O
2007	O
,	O
the	O
first	O
unofficial	O
translations	O
were	O
released	O
by	O
Lars	O
Wohlfahrt	O
before	O
Sumatra	B-Language
PDF	I-Language
got	O
official	O
multi-language	O
support	O
.	O
</s>
<s>
In	O
October	O
2015	O
,	O
version	O
3.1	O
introduced	O
a	O
64-bit	B-Device
version	O
,	O
in	O
addition	O
to	O
their	O
original	O
32-bit	O
version	O
.	O
</s>
<s>
The	O
graphics	O
design	O
of	O
Sumatra	O
is	O
a	O
tribute	O
to	O
the	O
cover	O
of	O
the	O
Watchmen	B-Application
graphic	O
novel	O
by	O
Alan	O
Moore	O
and	O
Dave	O
Gibbons	O
.	O
</s>
<s>
Sumatra	O
has	O
attracted	O
acclaim	O
for	O
its	O
speed	O
and	O
simplicity	O
,	O
for	O
being	O
portable	B-Application
,	O
its	O
keyboard	O
shortcuts	O
,	O
and	O
its	O
open-source	B-Application
development	I-Application
.	O
</s>
<s>
At	O
one	O
time	O
the	O
Free	B-Application
Software	I-Application
Foundation	O
Europe	O
recommended	O
Sumatra	B-Language
PDF	I-Language
,	O
but	O
then	O
removed	O
its	O
recommendation	O
in	O
February	O
2014	O
,	O
due	O
to	O
the	O
presence	O
of	O
the	O
non-freely	O
licensed	O
unrar	B-Application
code	O
in	O
Sumatra	O
.	O
</s>
<s>
Foundation	O
representative	O
Heiki	O
Ojasild	O
explained	O
,	O
"	O
while	O
they	O
continue	O
to	O
make	O
use	O
of	O
the	O
non-free	O
library	O
,	O
SumatraPDF	B-Language
cannot	O
be	O
recognised	O
as	O
Free	B-Application
Software	I-Application
"	O
.	O
</s>
<s>
Unrar	B-Application
was	O
eventually	O
replaced	O
with	O
a	O
free	O
alternative	O
in	O
version	O
3.0	O
,	O
making	O
it	O
100%	O
free	B-Application
software	I-Application
.	O
</s>
