<s>
Geographic	B-Application
Resources	I-Application
Analysis	I-Application
Support	I-Application
System	I-Application
(	O
commonly	O
termed	O
GRASS	B-Application
GIS	I-Application
)	O
is	O
a	O
geographic	B-Application
information	I-Application
system	I-Application
(	O
GIS	B-Application
)	O
software	O
suite	O
used	O
for	O
geospatial	O
data	O
management	O
and	O
analysis	O
,	O
image	B-Algorithm
processing	I-Algorithm
,	O
producing	O
graphics	O
and	O
maps	O
,	O
spatial	O
and	O
temporal	O
modeling	O
,	O
and	O
visualizing	O
.	O
</s>
<s>
It	O
can	O
handle	O
raster	B-Algorithm
,	O
topological	O
vector	O
,	O
image	B-Algorithm
processing	I-Algorithm
,	O
and	O
graphic	O
data	O
.	O
</s>
<s>
GRASS	B-Application
GIS	I-Application
contains	O
over	O
350	O
modules	O
to	O
render	O
maps	O
and	O
images	O
on	O
monitor	O
and	O
paper	O
;	O
manipulate	O
raster	B-Algorithm
and	O
vector	O
data	O
including	O
vector	O
networks	O
;	O
process	O
multispectral	O
image	O
data	O
;	O
and	O
create	O
,	O
manage	O
,	O
and	O
store	O
spatial	O
data	O
.	O
</s>
<s>
It	O
is	O
licensed	O
and	O
released	O
as	O
free	B-License
and	I-License
open-source	I-License
software	I-License
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
(	O
GPL	B-License
)	O
.	O
</s>
<s>
It	O
runs	O
on	O
multiple	O
operating	B-General_Concept
systems	I-General_Concept
,	O
including	O
,	O
Windows	B-Application
and	O
Linux	B-Application
.	O
</s>
<s>
Users	O
can	O
interface	O
with	O
the	O
software	O
features	O
through	O
a	O
graphical	B-Application
user	I-Application
interface	I-Application
(	O
GUI	B-Application
)	O
or	O
by	O
plugging	O
into	O
GRASS	O
via	O
other	O
software	O
such	O
as	O
QGIS	B-Application
.	O
</s>
<s>
They	O
can	O
also	O
interface	O
with	O
the	O
modules	O
directly	O
through	O
a	O
bespoke	O
shell	B-Operating_System
that	O
the	O
application	O
launches	O
or	O
by	O
calling	O
individual	O
modules	O
directly	O
from	O
a	O
standard	O
shell	B-Operating_System
.	O
</s>
<s>
The	O
latest	O
stable	O
release	O
version	O
(	O
LTS	O
)	O
is	O
GRASS	B-Application
GIS	I-Application
7	O
,	O
which	O
is	O
available	O
since	O
2015	O
.	O
</s>
<s>
GRASS	O
supports	O
raster	B-Algorithm
and	O
vector	O
data	O
in	O
two	O
and	O
three	O
dimensions	O
.	O
</s>
<s>
GRASS	O
is	O
designed	O
as	O
an	O
environment	O
in	O
which	O
tools	O
that	O
perform	O
specific	O
GIS	B-Application
computations	O
are	O
executed	O
.	O
</s>
<s>
Unlike	O
GUI-based	O
application	B-Application
software	I-Application
,	O
the	O
GRASS	O
user	O
is	O
presented	O
with	O
a	O
Unix	B-Application
shell	B-Operating_System
containing	O
a	O
modified	O
environment	O
that	O
supports	O
execution	O
of	O
GRASS	O
commands	O
,	O
termed	O
modules	O
.	O
</s>
<s>
The	O
environment	O
has	O
a	O
state	B-Application
that	O
includes	O
parameters	O
such	O
as	O
the	O
geographic	O
region	O
covered	O
and	O
the	O
map	B-Application
projection	I-Application
in	O
use	O
.	O
</s>
<s>
All	O
GRASS	O
modules	O
read	O
this	O
state	B-Application
and	O
additionally	O
are	O
given	O
specific	O
parameters	O
(	O
such	O
as	O
input	O
and	O
output	O
maps	O
,	O
or	O
values	O
to	O
use	O
in	O
a	O
computation	O
)	O
when	O
executed	O
.	O
</s>
<s>
Most	O
GRASS	O
modules	O
and	O
abilities	O
can	O
be	O
operated	O
via	O
a	O
graphical	B-Application
user	I-Application
interface	I-Application
(	O
provided	O
by	O
a	O
GRASS	O
module	O
)	O
,	O
as	O
an	O
alternative	O
to	O
manipulating	O
geographic	O
data	O
in	O
a	O
shell	B-Operating_System
.	O
</s>
<s>
The	O
libraries	O
and	O
core	O
modules	O
are	O
written	O
in	O
C	B-Language
.	O
Other	O
modules	O
are	O
written	O
in	O
C	B-Language
,	O
C++	B-Language
,	O
Python	B-Language
,	O
Unix	B-Application
shell	B-Operating_System
,	O
Tcl	B-Operating_System
,	O
or	O
other	O
scripting	O
languages	O
.	O
</s>
<s>
The	O
modules	O
are	O
designed	O
under	O
the	B-Operating_System
Unix	I-Operating_System
philosophy	I-Operating_System
and	O
hence	O
can	O
be	O
combined	O
using	O
Python	B-Language
or	O
shell	B-Operating_System
scripting	O
to	O
build	O
more	O
complex	O
or	O
specialized	O
modules	O
,	O
by	O
users	O
,	O
without	O
knowledge	O
of	O
C	B-Language
programming	I-Language
.	O
</s>
<s>
There	O
is	O
cooperation	O
between	O
the	O
GRASS	O
and	O
Quantum	B-Application
GIS	I-Application
(	O
QGIS	B-Application
)	O
projects	O
.	O
</s>
<s>
Recent	O
versions	O
of	O
QGIS	B-Application
can	O
be	O
executed	O
within	O
the	O
GRASS	O
environment	O
,	O
allowing	O
QGIS	B-Application
to	O
be	O
used	O
as	O
a	O
user-friendly	O
graphical	B-Application
interface	I-Application
to	O
GRASS	O
that	O
more	O
closely	O
resembles	O
other	O
graphical	O
GIS	B-Application
software	I-Application
than	O
does	O
the	O
shell-based	O
GRASS	O
interface	O
.	O
</s>
<s>
Another	O
project	O
exists	O
to	O
re-implement	O
GRASS	O
in	O
Java	B-Device
as	O
JGRASS	O
.	O
</s>
<s>
The	O
development	O
platform	O
was	O
Unix	B-Application
running	O
on	O
VAX	B-Device
hardware	O
.	O
</s>
<s>
Around	O
this	O
time	O
,	O
a	O
port	O
of	O
the	O
software	O
to	O
Linux	B-Application
was	O
made	O
.	O
</s>
<s>
In	O
1998	O
,	O
Markus	O
Neteler	O
,	O
the	O
current	O
project	O
leader	O
,	O
announced	O
the	O
release	O
of	O
GRASS	O
4.2.1	O
,	O
which	O
offered	O
major	O
improvements	O
including	O
a	O
new	O
graphical	B-Application
user	I-Application
interface	I-Application
.	O
</s>
<s>
In	O
October	O
1999	O
,	O
the	O
license	O
of	O
the	O
originally	O
public	B-Application
domain	I-Application
software	I-Application
GRASS	O
software	O
was	O
changed	O
to	O
the	O
GNU	B-License
GPL	I-License
in	O
version	O
5.0	O
.	O
</s>
<s>
For	O
example	O
,	O
it	O
is	O
used	O
to	O
estimate	O
potential	O
solar	O
photovoltaic	O
yield	O
with	O
r.sun	B-Application
.	O
</s>
<s>
,	O
the	O
latest	O
stable	O
release	O
version	O
(	O
LTS	O
)	O
is	O
GRASS	B-Application
GIS	I-Application
7	O
.	O
</s>
