[ECOS] Project ideas for graduate course

Klaas Gadeyne klaas.gadeyne@fmtc.be
Wed Aug 1 08:04:00 GMT 2007


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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