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Wolfgang
20 Feb 2007, 6:40 PM
Maybe this a bit off topic, but since the experts are there i still have some questions about licencing in general:

- How can one (the copyright holder) change the licence of the released code at a later time? (or can it only be done in a further release?)
- How can one (the copyright holder) release code (bin /src) in different licences (so more than one)?


Example:
Given that i am the copyright holder / author of code.
- I release my v1.0 under the GPL.
- Then i decide to release v1.1 under the LPGL.
- After that i decide to release v1.2 under some more strict "abc" licence.
- Next i decide to release v2.0 under the strict "abc" license and the LGPL licence.

Would that work?


Given it does, my understanding is that if i use Ext in the project above:
- i could use EXT under the LGPL variant for the release v1.0 and v1.1, because i keep the "copyleft" character of the LGPL.
- i need to use EXT under the CDL variant for release v1.2, because i changed to a more strict license which would be incompatible with the LGPL and their "copyleft" character.
- i could use the EXT with the LGPL for my release v2.0 under the LGPL, but need to use EXT with the CDL when giving away my v2.0 under the "abc" licence.

Is this correct?

Wolfgang

MrKurt
20 Feb 2007, 7:31 PM
The copyright holder can change their particular license at any time. They can simultaneously release software under as many licenses as they want. They can't, however, retroactively change a license.

A license isn't something weird and tough to understand, it's really just a set of conditions an IP owner sets.

The LGPL isn't quite as viral as the GPL. If you write software that makes heavy use of Ext, you can release it under pretty much any license you want. Any changes you make to Ext itself would be subject to the terms of the LGPL. If you distribute an Ext variant, you have to make your source changes available.

So, you can actually use the LGPL version of Ext for all of your scenarios. The "copyleft" portion of the LGPL would only apply to Ext and any changes you make to Ext.

Wolfgang
21 Feb 2007, 12:58 AM
So i could use the LGPL version of Ext in any project, regards of the license i release the project under?
And i would only have to provide the src of Ext, if i did a modification and use the LGPL variant?

In other words:
If i release a software under any license, use Ext in the LGPL variant, make no modifications to Ext, then i do not need to provide any src code?

MrKurt
21 Feb 2007, 9:25 AM
Correct.

Wolfgang
21 Feb 2007, 11:15 AM
Thanks a lot for clarification :D

jack.slocum
21 Feb 2007, 1:14 PM
Actually I believe according the license that isn't the case.

Here's the text from the relevent section:


A program that contains no derivative of any portion of the Library, but is designed to work with the Library by being compiled or linked with it, is called a "work that uses the Library". Such a work, in isolation, is not a derivative work of the Library, and therefore falls outside the scope of this License.

However, linking a "work that uses the Library" with the Library creates an executable that is a derivative of the Library (because it contains portions of the Library), rather than a "work that uses the library". The executable is therefore covered by this License. Section 6 states terms for distribution of such executables.

In the terms of the web, I would interpret this as:

Paragraph 1 would apply when you distribute your app and point people at Ext to download it. For example, how I have done with YUI (until this release). Ext *uses* YUI, but doesn't contain it.

Now if I was to distribute an application (say blog software) and it includes Ext with it (therefore "contains" it), then that software with fall under paragraph 2.

Will I police this? Of course not, but I just wanted to clarify what the license says. It might sense to take a look at section 6 as well. It has a few options that you can choose from.

Wolfgang
22 Feb 2007, 1:11 PM
Thanks for your reply.
Without being a lawer, I am pretty sure you are right.