Re: Plugins, libraries, licenses and Debian

[mru@kth.se (Måns Rullgård)]

Don Armstrong <don@donarmstrong.com> writes:

>> If I write a program and release it under some non-GPL licencse, and
>> *later* someone writes a plugin and releases it under the GPL, how
>> can the program possibly become a derived work of that plugin?
>
> No, the program itself doesn't, but the work plugin+program does.

I found this in the GPL FAQ:

"The GPL does not require you to release your modified version. You
are free to make modifications and use them privately, without ever
releasing them."

Storing the application and the plugin on a disk certainly doesn't
constitute a modification to either of them.  Loading the plugin will
created a derived work in RAM.  The derived work will never be
distributed, and is thus permitted by the above paragraph.

>> In my particular case, a plugin must implement one or more predefined
>> interfaces.  Several implementations of an interface can (and do)
>> exist independently.  Does this affect the situation in any way?
>
> Yes, assuming one of those implementation's licenses is compatible
> with the plugin,

What does it matter how other implementations are licensed?

> or the plugin is written to a generic interface and thus is a
> derived work of the generic interface as opposed to the
> implementation of that interface.

That is the case.

What about source distributions?  Is it allowed to distribute source
code licensed under the X11 license that uses a GPL'd library?

-- 
Måns Rullgård
mru@kth.se