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Re: Confused about LGPL terms - can you help?

From: Byron A Jeff
Subject: Re: Confused about LGPL terms - can you help?
Date: 25 Nov 2006 07:42:01 -0500

In article <>,
Alfred M. Szmidt <> wrote:

>   >I read the LGPL terms here:
>   >

>   >I would like to use an LGPL library for a commercial (and not open
>   >source) program I am writing.

>   The primary difference between the GPL and LGPL is that you can use
>   it in commercial projects.

>This is not correct, both the GPL and the LGPL can be used in
>commercial products.


Let's not be like Alex and argue legal semantics. The way that the GPL is
structured creates a situation where the monetary value of distributed
software tends to work its way towards $0. It works this way because the GPL
specifically requires source distribution of GPL software and prohibits
restrictions on further downline redistribution rights. So anyone who obtains
a cpoy of GPL software has the ability to redistribute it for no money.
Licenses and lack of source code both create artifical software scarcity
which causes that software to have a monetary value.

Any monetary value that GPL software retains is due to other factors. Either
the convenience of packaging, or other bundled services causes that retention. 
Or the possibility that some external factor keeps the recipient from
performing further redistribution.

So to say that GPL software can be used commercially in the same mode as
traditional closed source commercial software is disingenuous.

I'll correct my mistake though:

The primary difference between the GPL and the LGPL is that you can use
the LGPL in conjunction with closed source software. Whereas with the GPL
all conjoined source must also be GPLed.

>  All free software licenses allow this, it is one
>of important freedoms, and if this is not allowed it makes the license

Semantics. The GPL in particular enjoins a redistributor to distribute
the source and give any downline recipient the same right to redistribute
(for no monetary compensation) as the original redistributor.

These actions deflate any inherent monetary value of the redistributed

There's nothing wrong with the model. It facilitates the building of huge
software projects in a grassroots effort. When everyone brings one nail and
one stick to the party, you can build some really cool projects without
any one individual having to commit all of their resources to that project.

However the cost is that any inherent monetary value is distributed among
all the recipients. It's diluted.

Note that folks like Red Hat use trademark enforcement to embed inherent
monetary value, and associated redistribution restrictions, to their
software packages. If one could copy and redistribute an unmodified
 Redhat enterprise CD, trust me that folks would do so. Also any
support is associated with the original purchased CD, not any redistributed
copies. So once again, it's the the GPL that's driving the commercialism of
such an enterprise.

>   >My question is: Under such circumstances, will I be obliged by the
>   >license to make the source code of *my program* ( = "trade
>   >secret") available to the customer?

>   No. The LGPL has a few basic tenets:

>   1) Any changes to the library itself is subject to GPL terms.

>   >If so, how is LPGL different from GPL?

>   See above.

>The above is incorrect.  The Lesser GPL and the GPL only differ in
>what can be linked with.  A LGPL library can be used by
>GPL-incompatibly licensed programs, the same is not true for a GPL
>library, since it becomes a deriviate work of the library.

And exactly how does my point #1 above differ from your statement? I
don't see the relavence.

Stop arguing that the points that I'm making are wrong and clarify the
situation in practical, not idealistic, terms. The OP doesn't need a
debate on semantics. The OP needs to understand what they can and cannot
do with a LGPL library.

To reiterate to the OP: you can link your closed source software to an 
unmodified LGPL DLL without having to release your source. If you even make
any changes to the LGPL library, those changes must be distributed (or
an offer made) with the library. If you were using a GPL library, then all
source linked with the library to make a complete work must be distributed.

This isn't a sematics debate. I'm not Alex. I'm a GPL advocate trying to
get useful information to people.

P.S. Please don't CC my E-mail on a public news post. Thanks.


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