Well i wouldn’t say that if I was you if don’t take a look a the code first at least to reconsider it worth the effort improving/overhauling an already available algorithm that works but only needs some more love…
It’s definitely an option, I’ll look into it, but there are lots of things to consider especially if someone else is already maintaining it.
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Thanks. Looks neat. Do we add this like the typical addon?
Yes! Just click this link and download the latest version .zip file, then in Blender go to Edit > Preferences > Add-Ons > Install, and pick the .zip file. Blender will do the rest.
https://blender.stackexchange.com/questions/72095/license-issues-with-blender-addons
This is exactly what my lawyer told me. This is not the linux case. All addons have to give freedom to modify and share their sources. You can avoid that by including non-gpl executables and you don’t need to give sources straight away, only to those who own the program and ask for it (though ask a lawyer on that one).
Blender Market allows only GPL and MIT licenses for paid addons.
Even Python modules you import in the script have to be gpl-compliant.
I don’t really want to get into a licensing debate, but I’ll say a couple of things and hopefully we can leave it at that.
First of all my plugin is not on the blendermarket, so their rules don’t apply to me. But thanks for letting me know.
Second of all there are closed source plugins for Blender, and it wouldn’t make any sense for that not to be the case.
Third of all I’m not “linking”, as your stackexchange post says, to any GPL code. In fact I’m quite careful NOT to do that, precisely because I know about the GPL infection. In the worst case I might use LGPL, but I’ll never touch GPL.
And also if any of this was really a big problem, you would be severely limiting the people that want to create plugins for Blender and I very much doubt the Blender Foundation would want to cripple developers.
Anyway this plugin may or may not be open sourced in the future, I haven’t decided yet and am simply keeping my options open.
Back to coding…
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Blender also includes the Blender Python API, so every piece of code of the addon that uses some Blender Python API must be also licensed under GNU. This only applies to the addon script files or binaries.
You use Blender API which is GPL licensed… You use GPL code fragments in your code. I can’t put it simpler.
Can you give examples of closed source Blender addons that do not use executables?
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Sharing or selling Blender add-ons (Python scripts)
Blender’s Python API is an integral part of the software, used to define the user interface or develop tools for example. The GNU GPL license therefore requires that such scripts (if published) are being shared under a GPL compatible license. You are free to sell such scripts, but the sales then is restricted to the download service itself. Your customers will receive the script under the same license (GPL), with the same free conditions as everyone has for Blender.
Blender Foundation crippled you.
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Okay well I’ve deleted the plugin for now until I work out this possible licensing issue. Thanks for the information.
I hope I saved you some trouble in the future 
One more thing: there might be a way to use your closed source dll/pyd files with open sourced addon but I wouldn’t do that without a lawyer’s help. Look at this:
https://www.gnu.org/licenses/gpl-faq.en.html#GPLIncompatibleLibs
AGPL is about all kinds of communication with the code.
As I understand it, GPL only goes to the extent of dynamically linked libraries (this includes Python C and Cython modules), so if you use other IPC mechanics like TCP/IP to communicate with your closed source module, GPL does not apply.
I am not a lawyer and this is not legal advice.
I hope so.
As far as I’m aware this whole “what is linking” is a grey area, and it’s best to get as far away from the centre of it as possible. Ideally you’d want to stay away from GPL completely, and that’s only if Ton wants to sue plugin developers which I can’t imagine is a good idea for Blender’s reputation. Who’d want to make plugins for Blender then? It’s all very bizarre in my opinion. But oh well, I’ll sort it out and re-upload.
Linking is very well defined in computer science, both from operating system standpoint and from the executable standpoint. Just to add, there are countless so called “bridge addons” where the only GPL Python part is the communication between Blender and the closed source program, so I don’t see any issues with that.
Again, IANAL.
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I mean what constitutes whether you’re mixing GPL with non-GPL, linking in the colloquial / legal sense.
A pain in the ass is what it really is.
Well all IP and copyright law are a pain in the ass. That’s kind of the point. 
There’s always some party that is legally obligated to do something or not do something, when they really would like to.
In your case the problem lies in:
import bpy
Btw I doubt that Blender Foundation would sue you, but I would expect that from Free Software Foundation and some of your clients.
GPL does not go over communication lines. For example invoking Substance command line tool from a Blender addon does not make the Substance command line tool GPL. Copyright does not apply if there’s no copy.
Anyways @ziel is right it’s better to nip this in the bud now, I appreciate the advice from you and @ambi.
For those watching from the stands and wondering what’s going on, I’d just like to say that ideally I’d like my plugin to be freely available, but I do not want it to be tied to GPL.
The way I see it, the GPL license might give everyone else “freedom” to do whatever they want, but at the same time it takes freedom away from me as a developer. That isn’t fair in my opinion.
Even if I was to make the plugin open source, I wouldn’t use GPL for that, because then I’d be forcing other people that want to use my code to jump through hoops like I’m doing now. Forcing that on other people is not what I would call freedom either.
Anyway I’ll be going over my code with a fine toothed comb and then this plugin will return.
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