Addon license question

I've been thinking about using this CMS for a while. I've played with it a little bit, but haven't pulled the trigger. I've done some research, but I haven't found anything I feel comfortable with calling the answer.

Do the addons interact with Modx through an API, or do I need to include any Modx code in my addon. Reason for asking is because I may need to write an addon that I wouldn't want released. I would want to hold the license to it, and license it to the client only. Leaving all Modx licenses intact.

I understand that under GPL I do not have to release my code, but if I do, I have to release it under GPL. So, if I release it to the client I would have to release it as GPL which means they could then release it.

I come from a software development firm that builds proprietary software. So GPL is semi-mystical to me. I've used GPL CMSs for my own stuff, I've used them if I could do everything within the base CMS or existing addons, or I've coded the whole solution on my own. I've never mixed the 2. I don't mind creating GPL software, but there are instances where I may not want to release it under GPL.

1. Licenses have to do with distribution. You do not have to release code to the public that you do for a client, no matter what license it is in. If the client wants to distribute it, then and only then do licenses come into play.

2. See http://thrash.me/tech-and-modx/open-source-vs-open-core.html for how MODX views the GPL

So if I read your answer correctly 1. clearly means that anything created to work with Modx is GPL. It basically says the same thing above. So, if I release it to the client I would have to release it as GPL to the client which means they could then release it as GPL.

That is not correct. The MODx code itself is GPL, and your client can release it again if he wishes.

3rd-party add-ons can be distributed under whatever license you choose. They are not part of the core, and the library APIs your add-on uses are not part of your add-on, unless you actually copy any code from the MODx core into your add-on. So you can charge for your add-on, and/or limit its distribution as you choose.

The simpleCart add-on is an example of this. http://en.oostdesign.nl/modx-revolution-cms/modx-extras/simplecart-webshop/ It is released under a commercial, non-transferable license.

License Grant: Licensor hereby grants Licensee a Personal, Non-assignable & non-transferable, Commercial with terms, Including the rights to create but not distribute derivative works, Non-exclusive license, all with accordance with the terms set forth and other legal restrictions set forth in 3rd party software used while running Software.

What was meant is that licensing only comes into play if the code is being distributed. Between you and your client, the only issue would be copyright; is this a "work for hire", in which case it belongs to the client, or do you retain copyright. If you retain copyright, and do not choose to license your application for redistribution, then the client may not redistribute it. If it's a "work for hire" and belongs to your client, then he can do as he pleases with it, and you may not distribute it to anyone else. [ed. note: sottwell last edited this post 12 years ago.]

Thank you for the straight answer. That's what I was looking for.