Corba interfacesand GPL freedom

Iain Barker iain at
Sat Sep 13 21:15:05 UTC 2003

I am concerned whether a Corba interface can be used by non-free software to
circumvent the freedoms and requirements of the GPL license. I realise "mere
aggregation" vs the definition of a copyright derived work is a complex
scenario, so I will try to keep my posting generic.

A proprietary vendor could create non-free software that functionally would
amount to a derived work, without actually making a derived work within the
meaning of copyright law. Would this break the spirit of the GPL while
complying with its terms, hence not be enforcable?

I have seen the Corba 'serverizing' analogy discussed on this list, and have
looked around the FSF website for clarification but I don't see any position
statement from FSF addressing this issue. The nearest entry in the FSF
GPL-FAQ is the "pipes and sockets" definition, which suggests this form of
abstract inter-process communication is an acceptable mechanism for GPL
software to interwork with non-free modules.

I've also read the earlier license-discuss postings of Mr Perens, Mr
Stallman and others regarding the use of Corba in this manner. The absence
of a position from the FSF appears to be potentially damaging the GPL
community, which risks losing freedom to the proponents of non-free

Here is an example of Corba 'serverizing':

A GPL application is modified by a vendor of non-free software, who adds a
Corba server API to the application. The vendor releases the source code to
the GPL application and modifications per the GPL terms.

The vendor then creates a non-free Corba client application which uses that
API but incorporates none of the GPL code. The source code to the client
application is not released by the vendor. Non-free applications could also
be used as Corba servers to a GPL client application in the same manner.

Essentially the freedom of the GPL codebase is reduced either way around.

Iain W. Barker, FSF member 336. iain at
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