Re: Writing PDF files

[Jeffrey Creem <jeff@thecreems.com>]

On 10/18/2011 6:14 AM, Yannick Duchêne (Hibou57) wrote:
> Le Tue, 18 Oct 2011 12:03:38 +0200, Yannick Duchêne (Hibou57)
> <yannick_duchene@yahoo.fr> a écrit:
>> And according to http://plplot.sourceforge.net/ there already is an
>> Ada binding (otherwise, this a C story).
> Potentially appealing too, is the license, which is *L*GPL.
>
> However, it is not clear to me if with LGPL, you are required to
> dynamically link only or if you also can use static library link without
> fears. I just had a look at the Wikipedia entry, which is no more clear
> than my mind:
>
>> Essentially, if it is a "work that uses the library", then it must be
>> possible for the software to be linked with a newer version of the
>> LGPL-covered program. The most commonly used method for doing so is
>> to use "a suitable shared library mechanism for linking". Alternatively,
>> a statically linked library is allowed if either source code or
>> linkable object files are provided.
> What does that mean ? Which sources are you required to provide ? The
> one of the library or the one of the application statically linked to it ?
>



The idea behind the LGPL language there is that it must be technically 
possible to re-create the program in question and update/replace/bug 
fix/modify the portion that is covered by LGPL. Dynamic linking does 
this. Static linking can support this if you provide the required pieces 
to support it.

So, you could for example provide a binary and the source code to 
everything. If you don't want to do that, you could also provide the .o 
files for the application that you wish to keep licensed under terms 
other than the GPL such that one could re-link those .o files with the 
library (And, provide the scripts, makefile, information required to do 
the relink).

  Usually when I explain this, sw people immediately jump to the 
conclusion that this is silly because version 11.23 of the LGPL covered 
library may not be API compatible with version 11.24 so clearly this is 
not providing the user with anything they'd want. The license language 
is not asking you to warranty that there exists an continuing stream of 
LGPL library updates that will always link against the .o files of  your 
application, but providing them does allow users at least the freedom to 
fix bugs in the LGPL portion and create a new application.