I guess I'm still unsure about what the phrase "based on" and "derived from" means in the context of writing content and building a site based on plone and zope. My stuff wouldn't be able to work directly without plone and zope, but on the other hand, it's not an extension of plone and is not derived from it either. I'll have to keep poking around. On Mon, 6 Dec 2004 13:28:23 +1300, Phillip Hutchings <sitharus@gmail.com> wrote:

On Sat, 4 Dec 2004 14:16:32 -0500, Alan Snyder <alan8373@gmail.com> wrote:

...

Hi everyone. I have a sort-of off-topic question about zope, plone and the GPL. If I write an application that sits on top of plone by using the CMF and the plone components and such, how must my portions be licensed? I've not written anything yet but just to be sure, if i write plone stuff that calls plone and cmf and zope functions and objects, must that also be GPL'd. I was under the assumption that calling GPL software didn't required making your stuff GPL but if you were to write code inside a module that is already gpl'd - like expanding it, then you'd obviously have to gpl it because you're modifying code - not writing new code. Also, I know the zope license is ZPL and more commercially friendly than the gpl, but plone is gpl so obviously there is a boundary there that is being enforced correctly.

TIA

From the last time I got involved with this, anything that is based on or derived from (this, iirc, includes any product that relies on a GPL product to function) must be released under the GPL.

Of course, the GPL only states that anyone who obtains a copy of the software must also have the source code available at a cost no more than the media required to send them the source ($5 tops more or less). You don't actually have to give the source away, and you are allowed to charge for the software.

-- Phillip Hutchings http://www.sitharus.com/ sitharus@gmail.com / sitharus@sitharus.com