topic Re: Extensions licensing issue for Alfresco CE in Alfresco Archive

Extensions licensing issue for Alfresco CE

wvictor — Thu, 21 Aug 2008 10:33:15 GMT

Hi,This is our situation:We are developing a system that uses Alfresco in two ways:1. Java client running separately, remotely communicating with an Alfresco repository using the functions in alfresco-web-service-client.jar. The client is used as a back end to automatically add content to the reposi

Re: Extensions licensing issue for Alfresco CE

sbuckle — Fri, 22 Aug 2008 20:33:01 GMT

As I understand it, any extensions / plugins that you write for the community edition of Alfresco are subject to the terms of the GPL; in other words, if you distribute your application with those changes, e.g. you sell it, then you must also make the source code etc for those changes / extensions available.

Basically, the source code to any application that makes use of code released under a reciprocal license, such as the GPL, must be made available; the GPL essentially "infects" the application. A caveat to this is that you are not obliged to make your changes available IF the application is only used within your organization or is for personal use; in other words, if you don't distribute it.

Other licenses such as the Mozilla license and the LGPL are examples of partially closable licenses meaning they do allow you to write closed source plug-ins etc - if you make any changes to the core product then you must release those changes also. For example, you could write a closed source Firefox extension but you couldn't modify Firefox and distribute it without releasing your changes.

Those 15 lines of source code you want to keep closed source must be really good

Disclaimer: I'm not a lawyer, this is just my understanding of the various licenses. You have been warned

Re: Extensions licensing issue for Alfresco CE

wvictor — Mon, 25 Aug 2008 11:36:52 GMT

Yup! Those lines of source contain the end of world hunger, the cure for cancer, a vaccine for AIDS, and eternal world peace! 😉

So if understand this correctly, I can sell my extension, as long as I provide source. Also, the stand-alone app can remain closed, right?

Re: Extensions licensing issue for Alfresco CE

sbuckle — Tue, 26 Aug 2008 09:25:32 GMT

So if understand this correctly, I can sell my extension, as long as I provide source.

Yes; that is my understanding. You must include the source code with the binary distribution. Take a look at the FAQ - I've linked to the section on writing plug-ins but might be a good idea to read the rest of it as well: http://www.gnu.org/licenses/gpl-faq.html#GPLAndPlugins

Also, the stand-alone app can remain closed, right?

As long as your application is a completely separate application - a different process - doesn't use any of the Alfresco stuff and all you are doing is calling the web services API of an Alfresco repository, then as I understand it you can license it how you please. There is the concept of aggregation in the GPL (http://www.gnu.org/copyleft/gpl-faq.html#MereAggregation) meaning that you can distribute both GPL and non-GPL licensed code and the programs are treated as separate works with separate copyrights; it basically comes down to how the programs communicate, e.g. shared memory, inter-process communication etc.

Having said all of that you will still probably want to get all of this checked by a lawyer