Thanks for writing to clarify. In the first case, you're free to do so, but you now wholly own the support for that instance, since it's not something that anyone would otherwise know the extent of what was done. In essence, it's a fork of MODX, and not something that the source project should be obligated to support.
In your second case, the way MODX is licensed means that once you distribute it to a client, they're free to do as they wish with it. That means they could charge folks to install it and distribute it to someone else, who in turn could distribute it in the same manner, or even give it away for free. This is because you modified the core MODX application. The GPL places no restrictions on charging for software, but does offer protection for redistribution rights of either modified or non-modified GPL'd software (for anyone that receives a distribution).
Had you used public APIs to accomplish the same results, you could have licensed the functionality in a non-GPL manner and that would have been within the spirit and letter of the law, at least in the way that we interpret it at MODX.
[ed. note: rethrash last edited this post 7 years, 8 months ago.]
, MODX Co-Founder
Follow me on Twitter at @rthrash or catch my occasional unofficial thoughts at thrash.me
Thank you rthrash for the fast response,
Lets say I that I used MODx as it is, and that all my modifications were in terms of CMPs, Snippets, Chunks, Custom Resource Classes, and Templates. You mean that the only way to protect the whole product to be resold is to put those modifications in non-GPL licenses (I understood from previous posts that I can license that kind of modifications in the way I want)?
The problem is that if I want to give away to the community for example that Custom Resource Class, that'd be incompatible with the new licenses I used to protect the product. I guess there is not a way to protect from redistribution (with or without retribution) a single product as a whole, giving the possibility to share some parts of your modifications.
Thank you again for your time.