<s>
Xournal	B-Language
is	O
an	O
open	B-Application
source	I-Application
tool	I-Application
for	O
annotating	O
PDF	B-Application
files	I-Application
.	O
</s>
<s>
It	O
supports	O
pen	B-Device
,	O
mouse	B-Device
,	O
and	O
keyboard	B-Device
input	O
.	O
</s>
<s>
It	O
and	O
the	O
related	O
Xournal++	O
are	O
commonly	O
used	O
for	O
adding	O
annotations	O
and	O
electronic	O
signatures	O
to	O
PDF	B-Application
files	I-Application
,	O
especially	O
on	O
Linux	B-Application
desktops	O
.	O
</s>
<s>
Users	O
can	O
open	O
PDF	B-Application
files	I-Application
and	O
use	O
Xournal	B-Language
to	O
highlight	O
in	O
color	O
,	O
type	O
text	O
,	O
and	O
draw	O
diagrams	O
.	O
</s>
<s>
Xournal	B-Language
uses	O
the	O
Poppler	B-Language
program	O
library	O
to	O
render	O
the	O
PDF	B-Application
files	I-Application
.	O
</s>
<s>
Annotations	O
can	O
be	O
saved	O
in	O
the	O
program	O
's	O
.xoj	O
file	O
format	O
without	O
modifying	O
the	O
original	O
PDF	B-Application
file	I-Application
.	O
</s>
<s>
Users	O
can	O
export	O
a	O
separate	O
annotated	O
PDF	B-Application
.	O
</s>
<s>
The	O
related	O
project	O
Xournal++	O
uses	O
the	O
.xopp	O
file	O
extension	O
.	O
</s>
<s>
It	O
started	O
as	O
a	O
rewrite	O
of	O
Xournal	B-Language
in	O
C++	B-Language
,	O
but	O
has	O
since	O
grown	O
beyond	O
the	O
original	O
.	O
</s>
<s>
Xournal	B-Language
stopped	O
adding	O
new	O
features	O
in	O
2016	O
,	O
while	O
Xournal++	O
remains	O
under	O
active	O
development	O
in	O
2023	O
.	O
</s>
<s>
Although	O
Xournal++	O
is	O
not	O
formally	O
considered	O
the	O
successor	O
to	O
Xournal	B-Language
,	O
the	O
original	O
's	O
author	O
suggests	O
users	O
try	O
Xournal++	O
.	O
</s>
