The Industry choice

[Scott Robinson]

On Fri, 07 Jan 2005 12:06:42 -0800, Jeff Shannon <jeff at ccvcorp.com>
wrote:

>Bulba! wrote:
>
>> On 6 Jan 2005 19:01:46 -0500, aahz at pythoncraft.com (Aahz) wrote:
>> 
>> 
>>>>Note that the so-called 'viral' nature of GPL code only applies to 
>>>>*modifications you make* to the GPL software.  The *only* way in which 
>>>>your code can be 'infected' by the GPL is if you copy GPL source.
>> 
>> 
>>>That's not true -- consider linking to a GPL library.
>> 
>> 
>> Will someone please explain to me in simple terms what's
>> the difference between linking to LGPLed library and linking
>> to GPLed library - obviously in terms of consequences of
>> what happens to _your_ source code?
>> 
>> Because if there isn't any, why bother with distinguishing 
>> between the two?
>
>Releasing a product in which your code is linked together with GPL'ed 
>code requires that your code also be GPL'ed.  The GPL goes to some 
>lengths to define what exactly "linked together" means.

That looks like a typo.  The LGPL goes to great length to how you can
link to LGPL software without using either the LGPL or GPL.  The GPL
(linked to by fsf.org) merely states:

	2.  You may modify your copy or copies of the Program or any
	 portion of it, thus forming a work based on the Program, and
	copy and distribute such modifications or work under the terms
	of Section 1 above, provided that you also meet all of these
	conditions:

Note that the conditions are all those of any program released under
the GPL.  Whatever "forming a work based on the Program" means is
whatever you and the copyright owner agree to, or whatever copyright
law considers a derived work in areas you wish to release your code
into.  I would suggest consulting a lawyer before getting close to the
line, but you can expect that any legally enforceable restrictions
claimed by FSF and/or RMS to be legally binding on all software
released under the (L)GPL that the FSF owns the copyright of (they
encourage programmers to sign over copyright to the FSF itself).

>
>Releasing a product in which your code is linked together with LGPL'ed 
>code does *not* require that your code also be (L)GPL'ed.  Changes to 
>the core library must still be released under (L)GPL, but application 
>code which merely *uses* the library does not.  (I've forgotten, now, 
>exactly how LGPL defines this distinction...)
>
>Jeff Shannon
>Technician/Programmer
>Credit International

Scott Robinson