The Implicit License
Update: a follow-up has been posted.
I’ve been toying with this idea for a while now: an implicit license.
This basically means that when I publish content and I do not name a specific license (or do not declare full copyright) I am implicitly saying:
This work has no explicit license associated with it.
You are free to use and share it privately, and free to modify it, derive your own work from it and distribute it if you accept to use a free and open license, as the Open Source Initiative defines it or alternatively agree to apply my implicit license to the work you based on this work. Attribution is not needed, but it is appreciated.
However, if you want to use it in a proprietary setting, full copyright conditions apply, and you will need to contact me to ask permission. In that case, I reserve all rights.
If and when I decide to re-license this work, the implicit license will not apply anymore. In the event you already have a copy of this work from before the re-licensing, you may distribute, derive and modify that version from that work. If I re-license this work to full copyright, you will need to ask me permission (which you will most likely get), but only once for all the uses of each work.
I’m not really sure whether the IL falls under the OSI definition of Open Source. I am also not sure whether this is in any way legal. I may change the wording, some terms, completely revise it.
For that, I need your feedback.
And no, it is not in effect yet. I will publicly state when and if it will take effect, most likely on this blog. And if I do it, but later decide to withdraw it, I will do the same.

License, Terms of use, call it as you will.[/useless]
One problem: you allow to re-license under BSD, which allows prprietary, closed-source use, but do not permit closed-source use without asking permission.
Also: Are you sure you like *all* licenses accepted by OSI as open source? I think there is some horrible microsoft one in their selection.
Still, interesting in my opinion. “You can use this under (L/A)GPL2+, 3-clause-BSD/MIT/zlib, apache2 licenses.” could also work.
I wish there was something like this for art and it was popular 🙂 no more st00pid gpl/cc-by-sa incompabilities ^^
Thanks for the feedback!
>One problem: …
I hope it’s not a problem, because my intent was that works derived from mine have a different author, and thus should be able to allow closed-source use, even if it still has bits of my original work in it.
Perhaps a bit rephrasing could solve it?
>Also: Are you sure…
Interesting issue. You’re right in that the scope may be to wide, but your suggestion seems a bit to narrow to me. I’ll do some searching to make an ideal list.
>I wish…
Well, the IL is meant to be technology-agnostic (but perhaps that would need me to use a different list of allowed licenses than OSI’s?). 😉 Popularity is always the issue though. Perhaps linking to this blog can solve the problem? 😛
>works derived…
But simply adding the MIT license to your code would allow to re-license under a proprietary license. They wouldn’t even have to release the MIT-licensed version, as the MIT license does not require this. Only if they decided to release the code, the MIT license would be visible.
But is it possible to re-license something of which you are not the copyright holder? I thought even Public Domain requires you to make at least substantial changes to the original work before you can claim copyright.
The issue of hidden MIT-licensing is more worrisome though. I couldn’t take anyone to court that way, if they could just tack on an MIT license and claim they based their proprietary version on that.
Perhaps I could require people to contact me if they want to use my works with licenses that allow proprietary deriving, but that would make the IL substantially less valuable, since liberal licenses are a great thing.
There should be some way only Open Source projects/works can benefit from implicit licensing. If only we knew what that is…