Cisco Cisco IPICS Release 2.1 Licensing Information

 

> My assertion is that plug-ins are written to an interface, not a

> program.  Since interfaces are not GPL'd, a plug-in cannot be GPL'd

> until the plug-in and program are placed together and run.  That is

> done by the end user, not the plug-in creator.

 

I agree, but also disrespectfully disagree ;)

 

It's an issue of what a "plug-in" is - is it a way for the program to

internally load more modules as it needs them, or is it _meant_ to be a

public, published interface.

 

For example, the "system call" interface could be considered a "plug-in

interface", and running a user mode program under Linux could easily be

construed as running a "plug-in" for the Linux kernel. No?

 

And there, I obviously absolutely agree with you 100%: the interface is

published, and it's _meant_ for external and independent users. It's an

interface that we go to great lengths to preserve as well as we can, and

it's an interface that is designed to be independent of kernel versions.

 

But maybe somebody wrote his program with the intention to dynamically

load "actors" as they were needed, as a way to maintain a good modularity,

and to try to keep the problem spaces well-defined. In that case, the

"plug-in" may technically follow all the same rules as the system call

interface, even though the author doesn't intend it that way.

 

So I think it's to a large degree a matter of intent, but it could

arguably also be considered a matter of stability and documentation (ie

"require recompilation of the plug-in between version changes"  would tend

to imply that it's an internal interface, while "documented binary

compatibility across many releases" implies a more stable external

interface, and less of a derived work)

 

Does that make sense to you?

 

> I asked Richard to comment on several scenarios involving plug-ins

> explain whether or not they were in violation of the GPL.  So far he

> as only addressed one and has effectively admitted a hole.  This is

> the one I asked that he's responded to:

>     [A] non-GPL'd plug-in writer writes a plug-in for a non-GPL'd

>     program.  Another author writes a GPL'd program making the

>     first author's plug-ins compatible with his program.  Are now

>     the plug-in author's plug-ins now retroactively required to be

>     GPL'd?

>

> His response:

>     No, because the plug-in was not written to extend this program.