The themes are under GPL license. Therefore, Cypher, I think you should also distribute them under GPL.
@Zaccret : anyway, IMHO, I think you can consider that if you distribute an application in a bundle including the unmodified themes, you are not making a derivative work. Your application can reasonably be considered as independant of the themes, no ?
I looked into CSS files included in those themes and here is the license summary:
- Black theme - GPL;
- DarkGray theme - LGPL;
- Olive theme - LGPL;
- Purple theme - explicitely not defined but based on ExtJS 2.0 Alpha 1;
- Slickness theme - LGPL;
And because my GXT theme wrapper (10 lines of Java code) is "public domain", the license of the whole theme package is defined by license of theme resources - which is GPL or LGPL respectively. Should you have any license-related questions, please contact the original author.
There is a legal difference between a license and copyright.
An author always retains copyright automatically without doing anything. A license exist so others can use the works with conditions.
Copyright is law/legislation. Licenses are contracts/agreements between two parties (the author and the user).
GPL is a license and does nothing to restrict or limit copyright. Most legal systems in the world see contracts that attempt to restrict law as being void, so very few (if any) contract attempt to remove rights given under law (ie copyright).
An author can issue works with no license but will always retain copyright.
First of all, I'm not providing legal advice - you need to get that yourself.
Originally Posted by sdc
But does a work with no license = everybody can legally use it ?
Yes. If you distribute (ie make available with no restrictions) then you are allowing use with no license.
Originally Posted by sdc
By the way, I think we cannot say that they are in public domain, because public domain mean that there is no copyright on it.
Public domain is suggesting the works are commonly known things like a stick drawing of a man. Claiming ownership of all stick men drawings is not allowed as the concept is public domain (ie all folk know what a stick man is since 1st grade school).
Nobody really declares something as public domain as that is normally decided by courts or law - ie even if I write some clever software, claim it as public domain, I can later change my mind and make it copyright (as I am author that would be allowed). You would contest in court that it is public domain (probably by my previous claim that it was), and if correct, I would have no claim for copyright.
If the code in the themes are commonly known (and given there is only one way to bundle an ExtJS theme in GXT it would be) then it would be fair to believe that the works are public domain. Similar to worrying that Sun could lay a claim to copyrighting the use of certain MVC Java patterns - these are now commonly known across many different languages and use within Java is public domain. There is no reasonable copyright of the MVC pattern in java.
I respect the others folks opinions regarding zipping up jars but y'know, for someone who will benefit from your work and generosity, I think that is simply splitting hairs.
It was very easy for me to change the extension of the files as I downloaded and saved them.