<s>
Software	B-Application
categories	I-Application
are	O
groups	O
of	O
software	B-Application
.	I-Application
</s>
<s>
They	O
allow	O
software	B-General_Concept
to	O
be	O
understood	O
in	O
terms	O
of	O
those	O
categories	O
,	O
instead	O
of	O
the	O
particularities	O
of	O
each	O
package	O
.	O
</s>
<s>
Different	O
classification	O
schemes	O
consider	O
different	O
aspects	O
of	O
software	B-Application
.	I-Application
</s>
<s>
Computer	B-Application
software	I-Application
can	O
be	O
put	O
into	O
categories	O
based	O
on	O
common	O
function	O
,	O
type	O
,	O
or	O
field	O
of	O
use	O
.	O
</s>
<s>
Application	B-Application
software	I-Application
is	O
the	O
general	O
designation	O
of	O
computer	O
programs	O
for	O
performing	O
tasks	O
.	O
</s>
<s>
Application	B-Application
software	I-Application
may	O
be	O
general-purpose	O
(	O
word	B-General_Concept
processing	I-General_Concept
,	O
web	B-Application
browsers	I-Application
,	O
etc	O
.	O
)	O
</s>
<s>
Application	B-Application
software	I-Application
contrasts	O
with	O
system	B-Application
software	I-Application
.	O
</s>
<s>
System	B-Application
software	I-Application
is	O
a	O
generic	O
term	O
referring	O
to	O
the	O
computer	O
programs	O
used	O
to	O
start	O
and	O
run	O
computer	O
systems	O
including	O
diverse	O
application	B-Application
software	I-Application
and	O
networks	O
.	O
</s>
<s>
The	O
GNU	B-Operating_System
Project	O
categorizes	O
software	B-General_Concept
by	O
copyright	O
status	O
:	O
free	B-Application
software	I-Application
,	O
open	B-Application
source	I-Application
software	I-Application
,	O
public	B-Application
domain	I-Application
software	I-Application
,	O
copylefted	B-License
software	B-General_Concept
,	O
noncopylefted	O
free	B-Application
software	I-Application
,	O
lax	O
permissive	O
licensed	O
software	B-General_Concept
,	O
GPL-covered	O
software	B-General_Concept
,	O
the	B-Operating_System
GNU	I-Operating_System
operating	I-Operating_System
system	I-Operating_System
,	O
GNU	B-Operating_System
programs	O
,	O
GNU	B-Operating_System
software	B-General_Concept
,	O
FSF-copyrighted	O
GNU	B-Operating_System
software	B-General_Concept
,	O
nonfree	B-Application
software	I-Application
,	O
proprietary	B-Application
software	I-Application
,	O
freeware	B-License
,	O
shareware	B-License
,	O
private	O
software	B-General_Concept
and	O
commercial	B-Application
software	I-Application
.	O
</s>
<s>
Free	B-Application
software	I-Application
is	O
software	B-General_Concept
that	O
comes	O
with	O
permission	O
for	O
anyone	O
to	O
use	O
,	O
copy	O
and	O
distribute	B-Application
,	O
either	O
verbatim	O
or	O
with	O
modifications	O
,	O
either	O
gratis	O
or	O
for	O
a	O
fee	O
.	O
</s>
<s>
If	O
a	O
program	O
is	O
free	O
,	O
then	O
it	O
can	O
potentially	O
be	O
included	O
in	O
a	O
free	O
operating	O
system	O
such	O
as	O
GNU	B-Operating_System
,	O
or	O
free	O
versions	O
of	O
the	O
Linux	B-Application
system	O
.	O
</s>
<s>
Free	B-Application
software	I-Application
in	O
the	O
sense	O
of	O
copyright	O
license	O
(	O
and	O
the	O
GNU	B-Operating_System
project	O
)	O
is	O
a	O
matter	O
of	O
freedom	O
,	O
not	O
price	O
.	O
</s>
<s>
But	O
proprietary	B-Application
software	I-Application
companies	O
typically	O
use	O
the	O
term	O
"	O
free	B-Application
software	I-Application
"	O
to	O
refer	O
to	O
price	O
.	O
</s>
<s>
Open-source	B-Application
software	I-Application
is	O
software	B-General_Concept
with	O
its	O
source	O
code	O
made	O
available	O
under	O
a	O
certain	O
license	O
to	O
its	O
licensees	O
.	O
</s>
<s>
The	O
one	O
condition	O
with	O
this	O
type	O
of	O
software	B-General_Concept
is	O
that	O
when	O
changes	O
are	O
made	O
users	O
should	O
make	O
these	O
changes	O
known	O
to	O
others	O
.	O
</s>
<s>
One	O
of	O
the	O
key	O
characteristics	O
of	O
open	B-Application
source	I-Application
software	I-Application
is	O
that	O
it	O
is	O
the	O
shared	O
intellectual	O
property	O
of	O
all	O
developers	O
and	O
users	O
.	O
</s>
<s>
The	O
Linux	B-Application
operating	I-Application
system	I-Application
is	O
one	O
of	O
the	O
best-known	O
examples	O
of	O
a	O
collection	O
of	O
open-source	B-Application
software	I-Application
.	O
</s>
<s>
Copylefted	B-License
software	B-General_Concept
is	O
free	B-Application
software	I-Application
whose	O
distribution	O
terms	O
ensure	O
that	O
all	O
copies	O
of	O
all	O
versions	O
carry	O
more	O
or	O
less	O
the	O
same	O
distribution	O
terms	O
.	O
</s>
<s>
This	O
means	O
,	O
for	O
instance	O
,	O
that	O
copyleft	B-License
licenses	I-License
generally	O
disallows	O
others	O
to	O
add	O
additional	O
requirements	O
to	O
the	B-Application
software	I-Application
(	O
though	O
a	O
limited	O
set	O
of	O
safe	O
added	O
requirements	O
can	O
be	O
allowed	O
)	O
and	O
require	O
making	O
source	O
code	O
available	O
.	O
</s>
<s>
This	O
shields	O
the	O
program	O
,	O
and	O
its	O
modified	O
versions	O
,	O
from	O
some	O
of	O
the	O
common	O
ways	O
of	O
making	O
a	O
program	O
proprietary	B-Application
.	O
</s>
<s>
Some	O
copyleft	B-License
licenses	I-License
block	O
other	O
means	O
of	O
turning	O
software	B-General_Concept
proprietary	B-Application
.	O
</s>
<s>
Copyleft	B-License
is	O
a	O
general	O
concept	O
.	O
</s>
<s>
Different	O
copyleft	B-License
licenses	I-License
are	O
usually	O
"	O
incompatible	O
"	O
due	O
to	O
varying	O
terms	O
,	O
which	O
makes	O
it	O
illegal	O
to	O
merge	O
the	O
code	O
using	O
one	O
license	O
with	O
the	O
code	O
using	O
the	O
other	O
license	O
.	O
</s>
<s>
If	O
two	O
pieces	O
of	O
software	B-General_Concept
use	O
the	O
same	O
license	O
,	O
they	O
are	O
generally	O
mergeable	O
.	O
</s>
<s>
Noncopylefted	O
free	B-Application
software	I-Application
comes	O
from	O
the	O
author	O
with	O
permission	O
to	O
redistribute	O
and	O
modify	O
and	O
to	O
add	O
license	O
restrictions	O
.	O
</s>
<s>
If	O
a	O
program	O
is	O
free	O
but	O
not	O
copylefted	B-License
,	O
then	O
some	O
copies	O
or	O
modified	O
versions	O
may	O
not	O
be	O
free	O
.	O
</s>
<s>
A	O
software	B-General_Concept
company	O
can	O
compile	B-Language
the	O
program	O
,	O
with	O
or	O
without	O
modifications	O
,	O
and	O
distribute	B-Application
the	O
executable	B-Application
file	I-Application
as	O
a	O
proprietary	B-Application
software	I-Application
product	O
.	O
</s>
<s>
The	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
illustrates	O
this	O
approach	O
.	O
</s>
<s>
The	O
X	B-Operating_System
Consortium	O
releases	O
X11	B-Operating_System
with	O
distribution	O
terms	O
that	O
make	O
it	O
non-copylefted	O
free	B-Application
software	I-Application
.	O
</s>
<s>
However	O
,	O
nonfree	O
versions	O
are	O
available	O
and	O
workstations	B-Device
and	O
PC	O
graphics	B-Device
boards	I-Device
for	O
which	O
nonfree	O
versions	O
are	O
the	O
only	O
ones	O
that	O
work	O
.	O
</s>
<s>
The	O
developers	O
of	O
X11	B-Operating_System
made	O
X11	B-Operating_System
nonfree	O
for	O
a	O
while	O
;	O
they	O
were	O
able	O
to	O
do	O
this	O
because	O
others	O
had	O
contributed	O
their	O
code	O
under	O
the	O
same	O
non-copyleft	B-License
license	O
.	O
</s>
<s>
Shareware	B-License
is	O
software	B-General_Concept
that	O
comes	O
with	O
permission	O
to	O
redistribute	O
copies	O
but	O
says	O
that	O
anyone	O
who	O
continues	O
to	O
use	O
a	O
copy	O
is	O
required	O
to	O
pay	O
.	O
</s>
<s>
Shareware	B-License
is	O
not	O
free	B-Application
software	I-Application
or	O
even	O
semi-free	O
.	O
</s>
<s>
For	O
most	O
shareware	B-License
,	O
source	O
code	O
is	O
not	O
available	O
;	O
thus	O
,	O
the	O
program	O
cannot	O
be	O
modified	O
.	O
</s>
<s>
Shareware	B-License
does	O
not	O
come	O
with	O
permission	O
to	O
make	O
a	O
copy	O
and	O
install	O
it	O
without	O
paying	O
a	O
license	O
fee	O
,	O
including	O
for	O
nonprofit	O
activity	O
.	O
</s>
<s>
Like	O
shareware	B-License
,	O
freeware	B-License
is	O
software	B-General_Concept
available	O
for	O
download	O
and	O
distribution	O
without	O
any	O
initial	O
payment	O
.	O
</s>
<s>
Freeware	B-License
never	O
has	O
an	O
associated	O
fee	O
.	O
</s>
<s>
Things	O
like	O
minor	O
program	O
updates	O
and	O
small	O
games	O
are	O
commonly	O
distributed	O
as	O
freeware	B-License
.	O
</s>
<s>
Though	O
freeware	B-License
is	O
cost-free	O
,	O
it	O
is	O
copyrighted	O
,	O
so	O
other	O
people	O
ca	O
n't	O
market	O
the	B-Application
software	I-Application
as	O
their	O
own	O
.	O
</s>
<s>
They	O
are	O
:	O
platform	B-Device
and	O
management	B-Application
,	O
education	B-Application
and	O
reference	B-Application
,	O
home	O
and	O
entertainment	O
,	O
content	O
and	O
communication	O
,	O
operations	O
and	O
professional	O
,	O
product	O
manufacturing	O
and	O
service	O
delivery	O
,	O
and	O
line	O
of	O
business	O
.	O
</s>
<s>
Platform	B-Device
and	O
management	B-Application
—	O
Desktop	B-Application
and	O
network	O
infrastructure	O
and	O
management	B-Application
software	I-Application
that	O
allows	O
users	O
to	O
control	O
the	O
computer	O
operating	B-Application
environment	I-Application
,	O
hardware	B-Architecture
components	I-Architecture
and	O
peripherals	B-Device
and	O
infrastructure	O
services	O
and	O
security	O
.	O
</s>
<s>
Education	B-Application
and	O
reference	B-Application
—	O
Educational	B-Application
software	I-Application
that	O
does	O
not	O
contain	O
resources	O
,	O
such	O
as	O
training	O
or	O
help	B-Protocol
files	I-Protocol
for	O
a	O
specific	O
application	B-Application
.	O
</s>
<s>
Content	O
and	O
communications	O
—	O
Common	O
applications	O
for	O
productivity	B-Application
,	O
content	O
creation	O
,	O
and	O
communications	O
.	O
</s>
<s>
These	O
typically	O
include	O
office	O
productivity	B-Application
suites	O
,	O
multimedia	O
players	O
,	O
file	B-Application
viewers	I-Application
,	O
Web	B-Application
browsers	I-Application
,	O
and	O
collaboration	B-Protocol
tools	I-Protocol
.	O
</s>
<s>
Operations	O
and	O
professional	O
—	O
Applications	O
designed	O
for	O
business	O
uses	O
such	O
as	O
enterprise	O
resource	O
management	B-Application
,	O
customer	O
relations	O
management	B-Application
,	O
supply	O
chain	O
and	O
manufacturing	O
tasks	O
,	O
application	B-Application
development	O
,	O
information	B-Application
management	I-Application
and	O
access	O
,	O
and	O
tasks	O
performed	O
by	O
both	O
business	O
and	O
technical	O
equipment	O
.	O
</s>
