Re: Something about Less General Public License

[Byron A Jeff]

In article <1151247644.614592.44950@r2g2000cwb.googlegroups.com>,
Claude Yih <wing0630@gmail.com> wrote:

>Thanks for your kindness~~~

No problem. Glad to help out.

>> > 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.

>As a matter of fact, We got a new library by modifying the LGPL code
>and adding some our own code.

So for the sake of simplicity let's presume that all of the code would
have to be released as LGPL code.

>> > 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? 

>From your description above it's more like

>>Or is it:

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

>It is as follows:
>1) A non LGPL dynamic library
>2) Our code which is based on the LGPL code

Got it. You code needs to be released as LGPL. No worries about the
non LGPL dynamic library.

>> 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.

I think you answered that. Your code needs to be LGPLed.

>> > 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.

Which would be accomplished by releasing your code as LGPL since your
code is derivative from original LGPL code.

>> 2) Other code linked to LGPL code doesn't have to be licensed under the
>> LGPL.

That would be the dynamic library.

>> 3) binary only packages can be released.

So you would not have to release any code from the non LGPL dynamic library.
You'd only have to offer to release your own source derived from the original
LGPL code.

>1) Well, our source of the new will be free.

So everything is satisfied.

>2) You mean the shared library linked with our library should be
>distributed as well

The source? No. Distribute it any way its license permits. The LGPL doesn't
affect it at all.

> , but has not to be licensed under the LGPL?

Correct. Since it's not your code you can't relicense it anyway (unless of
course the original license permits it). It is not in any way impacted by
the LGPL code (either the original or your new code).

>Another question is that if a third party used our library, I mean
>statically or dynamically link, to create its own application or
>library, would its work has to be licensed under the LGPL?

Nope. That's the primary differentiator between the GPL and LGPL. With
the LGPL, anyone can "use" your library without having to license their
code as LGPL. However, if they "modify" your LGPL library (as you did with
the original LGPL code) then that code needs to be released under the LGPL.

BAJ