On 21 Jun 2001 11:39:37 -0400, Jim Penny wrote:
On Thu, Jun 21, 2001 at 05:18:40PM +0200, Federico Di Gregorio wrote:
On 21 Jun 2001 11:08:30 -0400, Jim Penny wrote: [snip]
OK, consider this from another point of view. If I have an operating system may I install a piece of GPL software on the operating system? May I redistribute the operating system? With the GPL software? May I invoke/run the GPL software?
My understanding is that the answer to every one of these is yes.
yes. only if it is free. only if it is free. yes, but only because gpl allows for gpl code linking with the major components of the os even if they are proprietary.
Uh, you might want to reconsider the "only if it is free" parts. After all Interix had a business of selling GPL software for a non-free OS. Now Microsoft has that business (NT Services for Unix Pack). IBM distributes gcc and perl. Cygwin sells GPL software for non-free OS's.
ops. ok, poorly worded. third parties can distribute only if the os is free, vendor can do as he please, obviously... [snip]
err, no. if you write an external module using only python code, as long as you use a gpl-compatible python to run zope, you can call your external code from zope. if you write a product suclassing dc code, you're effectively 'linking' and gpl limitations apply.
GPL limitations apply to whom: To you, the developer? To a downstream user invoking the product via dtml-call or dtml-var or their pythonish equivalents? To a downstream developer who modifies your product and redistibutes the modified product? To a downstream developer who writes a component that invokes the GPL component?
In my mind the only sensible answers are developer - no, user - no (but see Jerome Alet's codacil), downstream modifier - yes, downstream developer who uses - no.
The only other sensible option is that, indeed, no one may distribute GPL components for Zope, including the original developer.
as i said before, writing gpl code subclassing zope is a non-sense. even the author cannot, imho, redistribute its work with a plain gpl attached to it. the gpl says that if you link with gpl code *all* the code should be gpl or gpl-compatible (major os components like clibs, compilers, etc are an exception). so even the author cannot do that without licensing under gpl plus some exception ("as a special exception you're allowed to link this code with zope or any other zope product distributed under the zpl".) see the (in)famous gpl vs. qt thread in the debian mailing lists for an in-depth analisys of this problem. ciao, federico -- Federico Di Gregorio MIXAD LIVE Chief of Research & Technology fog@mixadlive.com Debian GNU/Linux Developer & Italian Press Contact fog@debian.org The number of the beast: vi vi vi. -- Delexa Jones