Embedding Bazaar into C/C++ applications

[Stephen J. Turnbull]

John Arbash Meinel writes:

 > There are lots of other niggles, like Meld being BSD but having an
 > abstract plugin architecture to handle a VCS system, and then writing a
 > plugin which conforms to that architecture, and itself imports bzrlib...
 > (Then the plugin could be gpl, but the program that imports the plugin
 > may not have to be, etc.)

The program that provides the abstract architecture for importing the
plugin does not have to be GPL, even under the FSF interpretation, as
long as the plugin was written to work with the abstract architecture
and not vice versa.  Cf readline-interface-compatible BSD programs.
(The FSF could conceivably sue to get rid of the readline-compatible
libedit.  But then what would happen is that another interface would
be created which all BSD programs would be converted to.  And some 3rd
party would write a GPLed wrapper for readline to target that
interface, leaving the FSF looking like a bully with no positive
results to show for its efforts.)  But if you distribute them both as
a single work (product),[1] you must distribute the importing program
under the GPL, too.

So I don't think this helps Brian's clients.  They don't want to say
"go to this other site and download X, Y, and Z and install them, and
by the way, we can't support those modules because that would imply
they're part of our product".


Footnotes: 
[1]  In practice, the "mere aggregation" clause won't help you here;
there had better be no copies of the GPLed plugin anywhere in your
public sites if you want to continue distributing the importing
program under a non-GPL license.