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Re: Project ideas for graduate course
- From: Klaas Gadeyne <klaas dot gadeyne at fmtc dot be>
- To: Andrew Lunn <andrew at lunn dot ch>
- Cc: ecos-discuss at ecos dot sourceware dot org
- Date: Wed, 1 Aug 2007 10:03:59 +0200 (CEST)
- Subject: Re: [ECOS] Project ideas for graduate course
- References: <97993dc40707300636w78cc9e7ct1d370872e9b11a0c@mail.gmail.com> <2a3305fe0707301026l128193f5ib904b30c5c7081b9@mail.gmail.com> <97993dc40707310034x25be6389t743929d93f368152@mail.gmail.com> <20070731093508.GE27886@lunn.ch> <Pine.LNX.4.64.0707311147340.13618@ampere.labo01.fmtc.be> <20070731100040.GF27886@lunn.ch> <Pine.LNX.4.64.0707311310060.13618@ampere.labo01.fmtc.be> <20070731121216.GG27886@lunn.ch> <Pine.LNX.4.64.0707311419560.13618@ampere.labo01.fmtc.be> <20070731130119.GH27886@lunn.ch>
On Tue, 31 Jul 2007, Andrew Lunn wrote:
I'm not sure (again :-) what you mean by "customer":
- a customer of FMTC that wants to sell a (closed source) product
based on eCos + EML pays a licence fee to FMTC, obtains a LGPL
version of EML and can create a closed source product, right? If
they want, they can modify the EML code [Let's call this customer
CustomerFoo]
Note: the LGPL version is exactly the same codebase, only provided a
with a different license. That code is "in the open" anyway with a
GPL license, so why would we object against CustomerFoo
redistributing the code.
Well, anybody can then pick up the LGPL version and avoid paying for
it! The GPL version then becomes redundant. So you might as well
distribute the LGPL version and remove the GPL version.
- a customer of CustomerFoo buys a closed source product. That's it.
Nope. Not quite. They buy the closed source produced, but also get a
copy of the sources to the open source parts. eg eCos and the LGPL
EtherCAT source. Plus, since you use the LGPL, you should supply the
customer with the object code files for the closes source parts. The
thing about the LGPL is that you are allowed to modify the LGPL code
and relink it with the none LGPL parts you got in object code form to
rebuild the application. This way, you can bug fix and extend the LGPL
parts.
I see, you are right! This means the LGPL license isn't suited for
that purpose.
Note that:
- FMTC doesn't consider the EML library as one of its core products,
that's the main reason we've put the code "out there" with a GPL
license for free (as in free beer).
- If someone would want to use this in a closed source product (and
hence make money out of it), the idea is they pay part of the
development cost to obtain a non-gpl license (but indeed the LGPL
isn't the license we want there).
Also, the customer is allowed to use eCos and the LGPL EtherCAT
themselves, since it is open source. They can distribute it, hack it,
do what they want under the GPL+exception and LGPL. However this is
where we might run into problems. the GPL(+exception) and LGPL is
transferable. The customer has just as many rights as the
distributor. However i suspect that the second license for the
EtherCAT is none transferable.
The GPL code is also licensed under another license at the same time
as being GPL. This i don't understand. How can it be GPL and something
else at the same time. This is where i would want copyright lawyers to
take a close look.
As I said, IANAL either :-), the exact "wording" from the license
comes from lawyers@beckhoff. However, as I understand it (and that
was the spirit of the license), you can consider it exactly the same
mechanism as above where you state that eCos is licensed under GPL
_plus_ exception. EML is GPL (or LGPL) + exception too, and the
exception says that derived code should be compliant with the EtherCAT
standard (in case you distribute/sell it, that is). So you should
consider the 2 licences as being complementary, not being something
else.
Well the eCos GPL+exception gives the user more rights. This is well
accepted in the community.
The exception for the EtherCAT i think removes rights. I think it
removes the right to redistribute and the right to redistribute is the
core of the (L)GPL licenses. That is one point i would want a
copyright lawyer to look at if i were considering using EtherCAT
sources.
It does not remove the right to redistribute (modified code) of EML,
as long as it stays compatible with the (open) EtherCAT standard (which I
think is not so unlogically?)
Klaas
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