GPLv3

[Ashley]

Hi,

Apologises in advance as this is probably the wrong section completely!

Basically, I have been using Kendo UI on one of my projects whilst it was in the beta stage. I can't afford the commercial license so want to use the GPLv3 version of Kendo UI. However, I'm not an expert on licensing at all. My current project will be open sourced (I don't know which license this will be under) and just wondered if anyone could list what implications the GPLv3 license might have on my current project.

Sorry again if this is in the wrong section but any help would be greatly appreciated.
Thanks

[Donna]

Hello Ashley,

Thank you for contacting us with your inquiry!

Kendo UI is dual-licensed, Commercial and Open Source (GPLv3). Unfortunately, due to the complexity of the GPL and the ambiguities inherent in copyright law, it is not appropriate for us to advise you on your specific licensing decisions. The best choice to determine which license is appropriate for your project would be to consult with your legal counsel.

Let me know if I can be of any additional assistance.

Best wishes,
Donna
the Telerik team

[briankb]

You will find better answers to this on Stackoverflow.com however I can summarize.

Best Practice: If in doubt buy a license. Which is exactly what they want you to do...

Specifically Telerik/KendoUI says that if you use their KendoUI libraries for commercial apps you must purchase a license.

This advice seems very contrary to the actual license they chose to use which is GPLv3. GPLv3 is more liberal. Since Javascript is plain text the source is always available via view-source. HOWEVER there are some gotcha's. There is no absolute consensus, at least not that I've found, about Javascript "linked" libraries like this one and many others. It's all just complicated mess and I believe it's very intentional by many vendors to push out a GPL version but never tell anyone that it's just fine to use it as long as you don't modify the source. Usually you only need to comply with a GPL type license if you MODIFY the source they provided. But again GPLv3 is more liberal than the GPL license. 

To be on the safe side and the bottom line is you must do what the vendor using the license requests. In this case Telerik requests that if you use the library in a commercial capacity you must purchase a license. Personally I think this is contrary to the GPLv3 license but I'm just a programmer and not a lawyer. ExtJS does this same thing and they have the same reply when asked.

If your project is truly open source I think (I'm NOT a lawyer!) you are safe. The GPLv3 gives you what I think is a do-over if you are using their code in a manner which they conclude is a violation of the license, in this case GPLv3.

Here is the Termination clause of the GPLv3

8. Termination.

You may not propagate or modify a covered work except as expressly provided under this License. Any attempt otherwise to propagate or modify it is void, and will automatically terminate your rights under this License (including any patent licenses granted under the third paragraph of section 11).

 

However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation.

 

Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice.

 

Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, you do not qualify to receive new licenses for the same material under section 10.

The second paragraph is the one to read carefully IMHO. Again I'm NOT a lawyer so this is my personal understanding of GPLv3. But it says if you are found to violate the license the copyright holder (Telerik in this case) must notify you and if it's your first violation you can resolve the issue by purchasing a license within 30 days of said notice. So basically you get a one time only amnesty if you receive a reasonable notification. 

[Ashley]

Thank you both for the replies. Although I am still confused about this issue you have provided me with some very useful information!

Thank you again
Ash

[briankb]

Unfortunately, there is no clear yes and no answer to these questions with GPLv3. 

Again I don't think GPLv3 fits with the spirit of what Telerik wants for KendoUI Open Source use.

At least they say it very plainly that they expect you to buy a license if your project is commercial (for money).