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APPENDIX
GNU
LESSER
GENERAL
PUBLIC
LICENSE
Version
2.1, February
1999
_>
-U
-U
m
Z
X
162
Copyright
(C) 1991,
1999
Free
Software
Foundation,
Inc.
51
Franklin
Street,
Fifth
Floor,
Boston,
MA
02110-1301
USA
Everyone
is permitted
to copy
and
distribute
verbatim
cop-
ies
of
this
license
document,
but
changing
it
is
not
allowed.
[This is the first released
version
of the Lesser
GPL
It also
counts
as
the
successor
of
the
GNU
Library
Public
License,
version
2, hence
the version
number
2.1.]
Preamble
The licenses
for most
software
are designed
to take away
your freedom
to share and change
it. By contrast,
the GNU
General
Public
Licenses
are intended
to guarantee
your
freedom
to share and change
free software
- to make sure
the software
is free for all its users.
This license,
the Lesser General
Public
License,
applies
to
some
specially
designated
software
packages
- typically
libraries
-
of the
Free
Software
Foundation
and
other
authors
who decide
to use it. You can use it too, but we
suggest
you first think
carefully
about
whether
this license
or the ordinary
General
Public
License
is the better
strat-
egy to use in any particular
case, based
on the explana-
tions
below.
When
we
speak
of free
software,
we
are
referring
to
free-
dom
of
use,
not
price.
Our
General
Public
Licenses
are
designed
to
make
sure
that
you
have
the
freedom
to
dis-
tribute
copies
of free
software
(and
charge
for
this
service
if you
wish);
that
you
receive
source
code
or can
get
it if you
want
it; that
you
can
change
the
software
and
use
pieces
of
it in
new
free
programs;
and
that
you
are
informed
that
you
can
do
these
things.
To protect
your
rights,
we need
to make
restrictions
that
forbid
distributors
to deny you these
rights
or to ask you to
surrender
these rights. These
restrictions
translate
to certain
responsibilities
for you if you distribute
copies
of the library
or if you modify
it.
For example,
if you distribute
copies
of the library, whether
gratis
or for a fee, you must
give the recipients
all the rights
that
we
gave
you.
You
must
make
sure
that
they,
too,
receive
or can get the source
code.
If you link other
code
with the library, you must
provide
complete
object
files to
the recipients,
so that they can relink them
with the library
after making
changes
to the library and recompiling
it. And
you must
show them
these
terms
so they know their
rights.
We protect
your rights with a two-step
method:
(1) we copy-
right
the
library,
and
(2) we offer
you this
license,
which
gives you legal permission
to copy, distribute
and/or
mod-
ify the library.
To protect
each
distributor,
we
want
to
make
it very
clear
that
there
is no warranty
for the free
library.
Also,
if the
library
is modified
by someone
else and
passed
on, the
recipients
should
know
that
what
they
have
is not
the
original
version,
so that the original
author's
reputation
will
not be affected
by problems
that might
be introduced
by
others.
Finally,
software
patents
pose
a constant
threat
to the
exis-
tence
of any
free
program.
We
wish
to
make
sure
that
a
company
cannot
effectively
restrict
the
users
of a free
pro-
gram
by
obtaining
a
restrictive
license
from
a
patent
holder.
Therefore,
we
insist
that
any
patent
license
obtained
for
a version
of the
library
must
be
consistent
with
the
full
freedom
of use
specified
in this
license.
Most
GNU
software,
including
some
libraries,
is covered
by
the
ordinary
GNU
General
Public
License.
This
license,
the
GNU
Lesser
General
Public
License,
applies
to certain
des-
ignated
libraries,
and
is
quite
different
from
the
ordinary
General
Public
License.
We
use
this
license
for
certain
libraries
in order
to
permit
linking
those
libraries
into
non-
free
programs.
When
a program
is linked
with
a library, whether
statically
or using
a shared
library,
the
combination
of the two
is
legally
speaking
a combined
work, a derivative
of the origi-
nal library.
The ordinary
General
Public
License
therefore
permits
such
linking
only if the entire
combination
fits its
criteria
of freedom.
The
Lesser
General
Public
License
permits
more
lax criteria
for
linking
other
code
with
the
library.
We call
this
license
the
"Lesser"
General
Public
License
because
it does
Less to protect
the user's
freedom
than
the ordinary
General
Public
License.
It also provides
other
free software
developers
Less of an advantage
over com-
peting
non-free
programs.
These
disadvantages
are the
reason
we use
the
ordinary
General
Public
License
for
many
libraries.
However,
the Lesser license
provides
advan-
tages
in certain
special
circumstances.
For example,
on rare occasions,
there
may
be a special
need
to encourage
the
widest
possible
use
of a certain
library,
so that it becomes
a de-facto
standard.
To achieve
this, non-free
programs
must
be allowed
to use the library.
A more
frequent
case is that a free library
does the same
job
as widely
used
non-free
libraries.
In this case, there
is
little to gain by limiting
the free library to free software
only,
so we use the Lesser
General
Public
License.
In other
cases,
permission
to use
a particular
library
in non-
free
programs
enables
a greater
number
of people
to use
a large
body
of free
software.
For example,
permission
to
use
the
GNU
C Library
in non-free
programs
enables
many
more
people
to
use
the
whole
GNU
operating
system,
as
well
as its variant,
the
GNU/Linux
operating
system.
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