<s>
VRR	B-Application
(	O
a	O
Vector-based	O
gRaphic	O
editoR	O
)	O
is	O
a	O
free	O
and	O
open-source	O
vector	B-Application
graphics	I-Application
editor	I-Application
application	O
designed	O
especially	O
for	O
creating	O
illustrations	O
of	O
mathematical	O
articles	O
.	O
</s>
<s>
VRR	B-Application
has	O
a	O
simple	O
but	O
powerful	O
operation	O
set	O
:	O
creating	O
,	O
manipulating	O
and	O
transforming	O
basic	O
graphic	O
primitives	O
,	O
which	O
are	O
points	O
,	O
segments	O
,	O
rational	O
Bézier	O
curves	O
,	O
elliptic	O
arcs	O
etc	O
.	O
</s>
<s>
VRR	B-Application
has	O
a	O
sophisticated	O
system	O
for	O
working	O
with	O
text	O
.	O
</s>
<s>
In	O
addition	O
to	O
common	O
text	O
objects	O
,	O
it	O
allows	O
you	O
to	O
create	O
text	O
objects	O
typeset	O
by	O
TeX	B-Application
and	O
make	O
them	O
part	O
of	O
your	O
image	O
.	O
</s>
<s>
The	O
editor	O
is	O
able	O
to	O
import	O
from	O
and	O
export	O
to	O
files	O
in	O
common	O
data	O
formats	O
(	O
export	O
to	O
PDF	B-Application
,	O
PS	B-Language
,	O
EPS	B-Language
and	O
SVG	B-Application
,	O
import	O
from	O
IPE5	B-Language
and	O
SVG	B-Application
)	O
.	O
</s>
<s>
VRR	B-Application
runs	O
on	O
Linux	B-Application
and	O
uses	O
a	O
graphical	B-Application
user	I-Application
interface	I-Application
based	O
on	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
and	O
GTK	B-Application
.	O
</s>
<s>
The	O
VRR	B-Application
project	O
was	O
started	O
as	O
a	O
student	O
project	O
at	O
Faculty	O
of	O
Maths	O
and	O
Physics	O
,	O
Charles	O
University	O
,	O
Prague	O
,	O
Czech	O
Republic	O
.	O
</s>
