Do I have to provide my CMS modifications under the GPL?

June 27, 2006 8:28 PM

Say I was using a Web Content Management System that was covered under the GPL. If I made lots of modifications to the CMS, but only used it for my own site - do I need to provide my modified CMS to the public to download? I'm debating this with a friend - I thought it was only if you are planning to redistribute the software to others, but now I'm wondering - and certainly don't want to a afoul of the GPL.
posted by Dag Maggot to law & government (6 comments total)

You're correct. You only need to provide the source if you redistribute modified GPL software.
posted by ijoshua at 8:30 PM on June 27, 2006

See here.
posted by ijoshua at 8:31 PM on June 27, 2006

Some consider this a loophole in the current GPL and intend to close it in the next revision of the license.
posted by NortonDC at 8:43 PM on June 27, 2006

Thanks ijoshua - perfect link.
posted by Dag Maggot at 8:46 PM on June 27, 2006

The Affero GPL is a modified version of the GPL that requires users of the covered software (e.g. via a web site) to be able to access its source. This eliminates the "ASP hole" in the GNU GPL.

The GPLv3 discussion draft includes language that would make the GNU GPL compatible with licenses like the Affero GPL, but it does not itself include an Affero-like clause.
posted by mbrubeck at 9:40 PM on June 27, 2006

Regarding NortonDCs statement.

The present version of the GPL was crafted at a time when commercial entities built systems that were used to provide services to individuals and organizations. It did not compel those companies to release their modifications to GPLed software to the users and customers of those services. I'd argue that this was neither an oversight, nor an accident.

It is true that some people consider this a loophole in the current GPL. They may well intend to see it closed in the next revision of the license, but that doesn't mean they have either the power or the influence to do so. Indeed, the latest draft of the v3 GPL does not appear to include any such provisions.

Finally, even if v3 of the GPL were released with provisions designed to compel the release of the modified versions of GPLed software used to provide services, v3 doesn't automatically apply to software distributed under the earlier versions of the GPL.
posted by Good Brain at 10:07 PM on June 27, 2006