We need a license
We need an "open source" license. Quotes around "open source" as this isn't code and it isn't a schematic or layout, it's more like art.
It doesn't seem like something like the GPL or the CERN OHL will really fit, they deal more with code and with a hardware design (this is not really either).
I don't want to release under something like Apache or a BSD/MIT license as that would allow others to not share their changes. But maybe this would actually be a good kind of license, to allow others to not share their changes, as that may drive more usage, especially if commercial people actually put up with KiCad. We can't put it in the public domain, because Germany.
Although I'm not a huge fan of the CreativeCommons licenses, but the CC-BY-SA would fit and likely do good things.
What do you think?