That was what we were discussing. Right now, our license is a mess, but whether the IDE is proprietary does not matter. In the future, I would like to continue to allow proprietary IDEs, so long as they do not do any of the following:
- Disguise the fact that ENIGMA is free software. Users should be aware that they have FOSS alternatives to the IDE, and that ENIGMA itself is free.
- Modify ENIGMA in any non-free way, which is forbidden by the GPL. All ENIGMA code must be open-source.
- Augment ENIGMA in any restrictive way; that is, offer non-free or specifically restricted extensions to ENIGMA which make it somehow more enticing to use the proprietary IDE (for reasons other than it is more intuitive, fast, or reliable than the free IDE).
So basically, as long as you're competing with your IDE, and not with ENIGMA, I have zero problem whatsoever with a proprietary IDE. I'd even encourage it in some cases. By competing with ENIGMA, I mean somehow getting ENIGMA itself to work better when used through your IDE; for example, by offering libraries or extensions that would not be available to users from another IDE that you do not control. In this case, I want the GPL to remain in full effect, so essentially, your options are to play nice and let everyone use your (proprietary) library (even if they have to pay for it), or to GPL it, in which case, everyone must use it open-source.
The simple answer to your question is, yes, you can have a proprietary IDE, as long as you don't try to be an asshole about it. Play fair, and no one will have a problem with it.