GPL-licensed binary plugins

[Iain Barker]

"Mikhail Gusarov" wrote:

> Yes, plugins and main program do share space, use callbacks and call
> each other. So I think in this case the main program is definitely
> GPL-ed (whohoo - this means that nearly everything on the device is
> GPL-covered).

It sounds likely, yes. But is not necessarily so, these 'grey area' 
situations are notoriously difficult, it very much depends how the 
individual implementation was done. I think some further investigation would 
be prudent before jumping to any conclusion publicly.

Ultimately it comes down to the definition of a 'derived work' - as the 
GPLv2 license is based on copyright law, not contract tort. If there is a 
well defined interface between the GPL and non-GPL parts, they may be 
considered entirely separate works and the GPL would not apply.

As a more practical example:

If the main program loads the plugin into memory and accesses it via an 
external interface (say for example, a Corba API which uses message 
passing), then there is no direct copyright derivation per-se; the plugin 
and the program can be argued to be completely separate works, merely 
communicating to each other via a public interface.

However, if the main program loads the plugin into memory and calls its 
functions directly (say for example, a dynamically linked library in the 
conventional sense), then most likely they are sharing intimate details of 
their sata structures etc;  the use of these internal semantics is what 
would constitute a 'whole based on the copyrighted work', and therefore 
copyright derivation and the GPL requirements for open source come into 
play.

As I said, it's a grey area and not 100% clear for your particular case. You 
can certainly try to approach the parties involved, and see if they are 
willing to comply without any further action. But I assume you aren't one of 
the actual copyright owners, so you wouldn't necessaily have any 'standing' 
to persue or enforece a claim under the GPL. In that case, you would be best 
off contacting the original author of the GPL code, and see if they are 
interested in asserting their copyright. If they are, consulting a copyright 
or other intellectual property lawyer or assigning the copyright to fsf and 
have them conduct a more detailed analysis might be easier than trying to 
persue it yourself.

IANAL, TINLA, YMMV etc.