Re: Something about Less General Public License

[Byron A Jeff]

In article <1150980860.937666.213140@u72g2000cwu.googlegroups.com>,
Claude Yih <wing0630@gmail.com> wrote:

>Hi, everyone. 

Hi.

>I don't know if it is right to discuss things about LGPL
>in this group.

It is.

> However, it seems that there is no particularly
>LGPL-oriented group, so I have to post this message here. Please
>forgive my boldness.

Nothing to forgive. You're in the right place.

>Our group is developing a library which contains some source code
>belongs to a library that is distributed under the terms of Less
>General Public License 2.1.

OK

> Of course, we know that we should distribute our library under 
> LGPL too.

Not necessarily. It all depends on the interaction between the
original LGPL code and your new code.

Two questions:

1) Did you modify any of the original LGPL code?

2) Is your system organized in such a way that a third party can
update that LGPL code?

The LGPL is specifically designed to link with non LGPL code. So 
long as the end user can access/update the LGPL code and it hasn't
been modified, you are under no obligation to license your new code
under the LGPL.

> However, in our library, it is
>dynamically linked with a shared library not covered by LGPL (this
>part is not the one belongts to the library covered by LGPL).

So you have three sets of code linked together:

1) An LGPL library
2) A non LGPL dynamic library.
3) Your code.

Right? Or is it:

1) A non LGPL dynamic library.
2) Your code which incorporates some LGPL code.

> But for some reason, it is impossible for us to distribute that 
> shared library under LGPL as well.

It's not yours to distibute under the LGPL. But it doesn't matter.
There's no requirement that code linked to LGPL code be licensed under
the LGPL. That's in fact the LGPL's entire purpose.

The only question that remains is how to license your code. And that
depends on how it interacts with the LGPL code.

> Our question is that if we distributed our library
>(binary and source code)   under the terms of  Less General Public
>License without providing the shared library together, would our
>activity be a violation of Less General Public License?

No matter one way or the other. If you license your code under the
LGPL, then without a doubt the LGPL license issues from the original
LGPL code has been addressed. The LGPL has three primary tenets:

1) LGPL code should remain free.
2) Other code linked to LGPL code doesn't have to be licensed under the
LGPL.
3) binary only packages can be released.

To meet the requirements of point #1, the source of any LGPL code and
derivatives should be made available. Since the shared library only
links to LGPL code, it's only subject to point #2, and can be licensed
and distributed under the owner license.

>
>Please help us with the question above. Your kindness will be
>appreciated. Thanks:)
>

Hope this clarifies.

BAJ