<s>
The	O
Q	B-Language
Public	I-Language
License	I-Language
(	O
QPL	B-Language
)	O
is	O
a	O
non-copyleft	B-License
license	O
,	O
created	O
by	O
Trolltech	O
for	O
its	O
free	B-Application
edition	O
of	O
the	O
Qt	B-Language
.	O
</s>
<s>
It	O
was	O
used	O
until	O
Qt	B-Language
3.0	O
,	O
as	O
Trolltech	O
toolkit	O
version	O
4.0	O
was	O
released	O
under	O
GPL	B-License
version	O
2	O
.	O
</s>
<s>
It	O
fails	O
the	O
Debian	B-License
Free	I-License
Software	I-License
Guidelines	I-License
,	O
used	O
by	O
several	O
Linux	B-Application
distributions	O
,	O
though	O
it	O
qualifies	O
for	O
the	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
's	O
Free	B-Application
Software	I-Application
Definition	I-Application
;	O
however	O
,	O
it	O
is	O
not	O
compatible	O
with	O
the	O
FSF	O
's	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
,	O
meaning	O
that	O
products	O
derived	O
from	O
code	O
under	O
both	O
the	O
GPL	B-License
and	O
the	O
QPL	B-Language
cannot	O
be	O
redistributed	O
.	O
</s>
<s>
KDE	B-Application
,	O
a	O
desktop	O
environment	O
for	O
Linux	B-Application
,	O
is	O
based	O
on	O
Qt	B-Language
.	O
</s>
<s>
Only	O
the	O
free	B-Application
open	O
source	O
edition	O
of	O
Qt	B-Language
was	O
covered	O
by	O
the	O
QPL	B-Language
;	O
the	O
commercial	O
edition	O
,	O
which	O
is	O
functionally	O
equal	O
,	O
is	O
under	O
a	O
pay-per-use	O
license	O
and	O
could	O
not	O
be	O
freely	O
distributed	O
.	O
</s>
<s>
Meanwhile	O
,	O
the	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
and	O
authors	O
of	O
the	O
GPL	B-License
objected	O
to	O
the	O
QPL	B-Language
as	O
it	O
was	O
a	O
non-copyleft	B-License
license	O
incompatible	O
with	O
the	O
GPL	B-License
.	O
</s>
<s>
As	O
KDE	B-Application
grew	O
in	O
popularity	O
,	O
the	O
free	B-Application
software	I-Application
community	O
urged	O
Trolltech	O
to	O
license	O
Qt	B-Language
under	O
the	O
GPL	B-License
to	O
ensure	O
that	O
it	O
would	O
remain	O
free	B-Application
software	I-Application
forever	O
and	O
could	O
be	O
used	O
and	O
developed	O
by	O
commercial	O
third	O
parties	O
.	O
</s>
<s>
Eventually	O
,	O
under	O
pressure	O
,	O
Trolltech	O
dual-licensed	O
the	O
free	B-Application
edition	O
of	O
Qt	B-Language
2.2	O
for	O
use	O
under	O
the	O
terms	O
of	O
the	O
GPL	B-License
or	O
the	O
QPL	B-Language
.	O
</s>
<s>
Other	O
projects	O
that	O
have	O
adopted	O
the	O
Q	B-Language
Public	I-Language
License	I-Language
,	O
sometimes	O
with	O
a	O
change	O
in	O
the	O
choice	O
of	O
jurisdiction	O
clause	O
,	O
include	O
:	O
</s>
<s>
Hercules	B-Application
,	O
a	O
software	O
implementation	O
of	O
the	O
System/370	B-Device
,	O
ESA/390	O
,	O
and	O
z/Architecture	B-Device
mainframe	O
computer	O
architectures	O
.	O
</s>
<s>
Tgif	B-Application
switched	O
from	O
a	O
free-of-charge	O
non-commercial	O
license	O
to	O
the	O
Q	B-Language
Public	I-Language
License	I-Language
.	O
</s>
<s>
Previous	O
projects	O
using	O
the	O
Q	B-Language
Public	I-Language
License	I-Language
include	O
:	O
</s>
<s>
The	O
OCaml	B-Language
compiler	O
and	O
related	O
tools	O
from	O
Projet	O
Cristal	O
at	O
INRIA	O
.	O
</s>
<s>
Since	O
April	O
2016	O
OCaml	B-Language
is	O
released	O
under	O
the	O
GNU	B-Application
Lesser	I-Application
General	I-Application
Public	I-Application
License	I-Application
version	O
2.1	O
with	O
linking	O
exception	O
.	O
</s>
<s>
CGAL	B-Language
for	O
versions	O
3.x	O
.	O
</s>
<s>
The	O
CGAL	B-Language
library	O
is	O
released	O
under	O
GNU	O
General	O
Public	O
License/LGPL	O
since	O
CGAL	B-Language
version	O
4.0	O
(	O
March	O
2012	O
)	O
.	O
</s>
<s>
The	O
Debian	O
project	O
rejects	O
software	O
covered	O
by	O
solely	O
QPL	B-Language
(	O
and	O
not	O
dual	O
licensed	O
with	O
something	O
else	O
like	O
the	O
GPL	B-License
)	O
because	O
of	O
:	O
</s>
