ZPL and GPL: What should one consider when choosing a license?
Recently, someone wrote to me regarding one of my z3c packages which is licensed under the GPL. They asked me to license them under the ZPL saying that the ZPL would allow the widest range of use for those packages. They also implied that using the GPL impacted the licensing of other code that uses mine. Mostly this is just a debate I've never taken up before. I've always just chosen the GPL because it's the most aligned with my values and ideals on a "visceral" level. IOW, it's a gut choice not an educated choice. I realize this is an old debate. I found some lengthy threads on zope-dev from 2001, but I think there have been some license changes since then. I also read the following blog posts: http://radio.weblogs.com/0116506/2005/11/21.html#a370 http://awkly.org/2005/11/21/gpl-considered-harmful/ Unfortunately, the comment by Chris McDonough mentioned in the latter doesn't seem to be accessible any more. I'd love to read it.
From those blog posts, I don't really see any corroboration of the claims of the person who made the request that I switch to the ZPL. What exactly about the GPL narrows the range of developers who can use my code? What about the GPL impacts the license of other code that depends on my code?
Here's what I want. I want anyone who modifies or forks my code to make their modifications just as accessible to myself and the community as my code is in the first place. I also want anyone who forks my code to credit me and other contributors as authors of the code they forked. I have a slight preference to allow proprietary code to depend on my code without having to open source their code. I definitely want commercial entities to be allowed to sell products and services that include my code as long as credit is given to the authors. That's just what I want from my admittedly naive perspective. I'd like to hear comments on why others think I should or shouldn't want any of those things from a license. I'd also like to hear how others think the license available relate to what I want from a license. Thoughts? Is there documentation somewhere about choosing a license? Maybe a howto I missed in my googling? Ross
On Fri, 21 Dec 2007, Ross Patterson wrote:
credit me and other contributors as authors of the code they forked. I have a slight preference to allow proprietary code to depend on my code without having to open source their code. I definitely want commercial entities to be allowed to sell products and services that include my code as long as credit is given to the authors.
Wouldn't that require use of the LGPL instead of the straight GPL? Then again, with web applications and such, that's probably going to involve some hair splitting.
On Dec 21, 2007, at 3:53 PM, Ross Patterson wrote:
Unfortunately, the comment by Chris McDonough mentioned in the latter doesn't seem to be accessible any more. I'd love to read it.
It said: """ I don't think Plone is "bad" because it uses the GPL. I do think it's a pain in the balls to have to ask authors of various GPL things if they're willing to relicense ZPL or other BSD-type license in order to be able to incorporate their software into CMF or Zope (as required by the ZC contributor's agreement in order to check it into either of those projects). It just puts up a big enough impediment to sharing code that the codebases don't intermingle much. What's gauche about using the GPL is that at least by default, the Plone guys don't need to ask the Zope guys if they can ship their software. They get the benefit (or pain ;-) of shipping it all without any extra work. But the Zope guys need to go track down the copyright owners of various bits of Plone code and get all of their permissions to ship their software in CMF or Zope via a relicense. That's just hurts collaboration badly. It's anti-sharing which I think is practically just gauche. """ Now I've gotta run out of here before a licensing discussion breaks out. ;-) - C
Chris McDonough <chrism@plope.com> writes:
On Dec 21, 2007, at 3:53 PM, Ross Patterson wrote:
Unfortunately, the comment by Chris McDonough mentioned in the latter doesn't seem to be accessible any more. I'd love to read it.
It said:
""" I don't think Plone is "bad" because it uses the GPL. I do think it's a pain in the balls to have to ask authors of various GPL things if they're willing to relicense ZPL or other BSD-type license in order to be able to incorporate their software into CMF or Zope (as required by the ZC contributor's agreement in order to check it into either of those projects). It just puts up a big enough impediment to sharing code that the codebases don't intermingle much. What's gauche about using the GPL is that at least by default, the Plone guys don't need to ask the Zope guys if they can ship their software. They get the benefit (or pain ;-) of shipping it all without any extra work. But the Zope guys need to go track down the copyright owners of various bits of Plone code and get all of their permissions to ship their software in CMF or Zope via a relicense. That's just hurts collaboration badly. It's anti-sharing which I think is practically just gauche. """
Thanks for digging that up, its a really good point to have in the mix here.
Now I've gotta run out of here before a licensing discussion breaks out. ;-)
I suppose this topic is just too volatile, but it would be great to have some documentation somewhere for developers like myself who don't really have strongly formed opinions or practices on licensing. I'd love to have a page I can go to, read the facts, a sampling of the opinions, all provided just for the purposes of giving developers a resource for making their own decision. Ross
Ross Patterson <me@rpatterson.net> writes:
Chris McDonough <chrism@plope.com> writes:
On Dec 21, 2007, at 3:53 PM, Ross Patterson wrote:
Now I've gotta run out of here before a licensing discussion breaks out. ;-)
I suppose this topic is just too volatile, but it would be great to have some documentation somewhere for developers like myself who don't really have strongly formed opinions or practices on licensing. I'd love to have a page I can go to, read the facts, a sampling of the opinions, all provided just for the purposes of giving developers a resource for making their own decision.
I'm really a bit embarrassed that I started this thread. All I really wanted was to find or maybe instigate the creation of resources for developers such as myself who want to learn enough about the licenses available to make a choice. I don't want to participate in or instigate a licensing debate. This is not to say I don't think it's worth debating. I think impassioned opinions and debates about licensing are necessary and healthy. It's just not why I started this thread. The amusing thing is much of the most useful information I've gotten has been off list. :) It seems as though a creating an informative resource on licensing in the Zope and/or Plone communities is not possible due to these impassioned opinions. As such, I'd like to to consider that conclusion to be the resolution of this thread. :) Ross
--On 26. Dezember 2007 18:56:43 -0800 Ross Patterson <me@rpatterson.net> wrote:
The amusing thing is much of the most useful information I've gotten has been off list. :)
It seems as though a creating an informative resource on licensing in the Zope and/or Plone communities is not possible due to these impassioned opinions. As such, I'd like to to consider that conclusion to be the resolution of this thread. :)
You'll can solve the gap between the followers of the purity of the GPL and people just trying to their job and money. My-last-2-cents-on-this-topic, Andreas
Hi Ross. The ZPL is a brief and concise license. It is clear on providing attribution of authors and copyright. The other requirements it imposes are fairly minimal. Other than this, it permits the code to be used in virtually any manner. The components in the Zope repository upon which Zope and Plone depend upon are licensed this way. It is roughly equivalent to BSD or MIT license. These are liberal licenses and in wide use. TurboGears, Twisted, Zope, and Django all use similar licensing. The rationale for these liberal licenses is more or less that the use of the licensed code does not impact code using it (other than for the user of the code to include the license in the source and perhaps identify last date of change in mixed sources). This means that not all code or derivatives using the licensed code need be disclosed but when it is offered it must contain the licensing in the source. Mixing code that GPL with nonGPL code on the other hand generally in a derivative that is GPL almost without exception. The requirements and disclosures required by derivative code is detailed in the GPL. In any case, licensing is a thorny issue. No one really wishes to debate it since it often digresses into heated and divisive exchanges on moral, social or commercial benefit or consequence. That said, it remains a necessary consideration for developers and businesses in relation to their intellectual assets (and also the responsibility one assumes when working with open source). In relation to Chris's post, my understanding of the Zope repository is that a committer is required to sign an agreement with Zope Corp or ZF. This requires the code to be licensed as ZPL with 50% of intellectual rights to Zope Corp or ZF. Hope this helps. Regards, David Ross Patterson wrote:
Recently, someone wrote to me regarding one of my z3c packages which is licensed under the GPL. They asked me to license them under the ZPL saying that the ZPL would allow the widest range of use for those packages. They also implied that using the GPL impacted the licensing of other code that uses mine.
Mostly this is just a debate I've never taken up before. I've always just chosen the GPL because it's the most aligned with my values and ideals on a "visceral" level. IOW, it's a gut choice not an educated choice.
I realize this is an old debate. I found some lengthy threads on zope-dev from 2001, but I think there have been some license changes since then. I also read the following blog posts:
http://radio.weblogs.com/0116506/2005/11/21.html#a370 http://awkly.org/2005/11/21/gpl-considered-harmful/
Unfortunately, the comment by Chris McDonough mentioned in the latter doesn't seem to be accessible any more. I'd love to read it.
From those blog posts, I don't really see any corroboration of the claims of the person who made the request that I switch to the ZPL. What exactly about the GPL narrows the range of developers who can use my code? What about the GPL impacts the license of other code that depends on my code?
Here's what I want. I want anyone who modifies or forks my code to make their modifications just as accessible to myself and the community as my code is in the first place. I also want anyone who forks my code to credit me and other contributors as authors of the code they forked. I have a slight preference to allow proprietary code to depend on my code without having to open source their code. I definitely want commercial entities to be allowed to sell products and services that include my code as long as credit is given to the authors.
That's just what I want from my admittedly naive perspective. I'd like to hear comments on why others think I should or shouldn't want any of those things from a license. I'd also like to hear how others think the license available relate to what I want from a license.
Thoughts? Is there documentation somewhere about choosing a license? Maybe a howto I missed in my googling?
Ross
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David Pratt <fairwinds@eastlink.ca> writes:
In relation to Chris's post, my understanding of the Zope repository is that a committer is required to sign an agreement with Zope Corp or ZF. This requires the code to be licensed as ZPL with 50% of intellectual rights to Zope Corp or ZF. Hope this helps.
And if we set up a licensing howto, it could also say something like, "If your code is on svn.zope.org then it *has* to be ZPL due to the contributor agreement you signed, dumbass!" :) I'll be fixing the licensing on my svn.zope.org projects as soon as I can carve out the time. Thanks for the heads up. Ross
Ross Patterson wrote:
Recently, someone wrote to me regarding one of my z3c packages which is licensed under the GPL. They asked me to license them under the ZPL saying that the ZPL would allow the widest range of use for those packages. They also implied that using the GPL impacted the licensing of other code that uses mine.
Mostly this is just a debate I've never taken up before. I've always just chosen the GPL because it's the most aligned with my values and ideals on a "visceral" level. IOW, it's a gut choice not an educated choice.
I realize this is an old debate. I found some lengthy threads on zope-dev from 2001, but I think there have been some license changes since then. I also read the following blog posts:
http://radio.weblogs.com/0116506/2005/11/21.html#a370 http://awkly.org/2005/11/21/gpl-considered-harmful/
Unfortunately, the comment by Chris McDonough mentioned in the latter doesn't seem to be accessible any more. I'd love to read it.
From those blog posts, I don't really see any corroboration of the claims of the person who made the request that I switch to the ZPL. What exactly about the GPL narrows the range of developers who can use my code? What about the GPL impacts the license of other code that depends on my code?
Here's what I want. I want anyone who modifies or forks my code to make their modifications just as accessible to myself and the community as my code is in the first place. I also want anyone who forks my code to credit me and other contributors as authors of the code they forked. I have a slight preference to allow proprietary code to depend on my code without having to open source their code. I definitely want commercial entities to be allowed to sell products and services that include my code as long as credit is given to the authors.
That's just what I want from my admittedly naive perspective. I'd like to hear comments on why others think I should or shouldn't want any of those things from a license. I'd also like to hear how others think the license available relate to what I want from a license.
Thoughts? Is there documentation somewhere about choosing a license? Maybe a howto I missed in my googling?
Ross
On Dec 21, 2007, at 12:53 PM, Ross Patterson wrote:
[snip some stuff about GPL versus ZPL]
Guys... please don't crosspost. It's hard to follow a thread like this when it gets fragmented across different lists. If you feel the need to solicit advice from multiple communities then IMHO it's much more useful (and less likely to devolve into a flame war) to start a separate thread for each. For my part, I'm going to just pick one list and respond there -- I'm guessing that zope@zope.org is most germane. Thanks, Ric
+-------[ Ross Patterson ]---------------------- | [snip] | code is in the first place. I also want anyone who forks my code to | credit me and other contributors as authors of the code they forked. It is this precise requirement that makes the 3-clause BSD license GPL incompatible. | I | have a slight preference to allow proprietary code to depend on my code | without having to open source their code. I definitely want commercial | entities to be allowed to sell products and services that include my | code as long as credit is given to the authors. You should consider a license that has that requirement then. There aren't many that do. -- Andrew Milton akm@theinternet.com.au
participants (7)
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Andreas Jung -
Andrew Milton -
Chris McDonough -
David Pratt -
Jeff Gentry -
Ricardo Newbery -
Ross Patterson