The OpenStreetMap project changed the licence of the data a few years ago (for Complicated Reasons™). People had to be contacted and ask to relicence their data, and eventually some data had to be deleted.
There is now a Contributor Terms¹ which governs how the licence can be changed. It requires a two thirds majority of active contributors (at least one change in at least 3 of the last 12 months, a working email address and replies to an email within 3 weeks) to approve a change to an "other free and open licence".
Good, but IMO far from watertight. They do not define what “free” and “open” mean. Presumably this refers to Free Software and Open Source licenses, but data isn’t software, so it cannot fully mean that. Also, I’m not sure all contributors would be happy if they moved to a license analogous to the GPL (that would mean users combining openStreetMap data with their own data would have to release their data under a similar license)
As it stands, worst-case, the data can, in theory, get locked up in two steps. Step one would move to a “free and open” license that doesn’t include the requirement to keep the license “free and open”, step two would take it commercial.
Also, reading that license for corner cases, what is the legal meaning of “worldwide”? Would it be legal to use OpenStreetMap data from orbit? From a moon observatory? From Mars?
2. OSM already has a sharealike licence, albeit more akin to LGPL than GPL
3. No, you misunderstand entirely. The Contributor Terms and the current choice of licence (the Open Database Licence) are separate. Even if OSM changes licence, the same Contributor Terms still apply, and those continue to mandate a free and open licence. There is no way to move to a non-open licence without breaking the terms under which every mapper has agreed to contribute their data.
(Even if you did: why? The OSM Foundation is intentionally light - it's a million miles away from the Wikimedia Foundation. Its assets are the domain name and trademark, a very small amount of hardware, and one part-time staff member. You could fork OSM trivially if the Foundation decided to "close the dataset", i.e. hosted a non-open dataset on openstreetmap.org.)
> Also, reading that license for corner cases, what is the legal meaning of “worldwide”? Would it be legal to use OpenStreetMap data from orbit? From a moon observatory? From Mars?
I guess that you have similar issues with Apache 2.0 (which also uses the term "worldwide"), GPLv3 (it uses "worldwide" for the patent grant), MPLv2, all of the Creative Commons licenses, etc.
"Worldwide" is a very commonly used term in license texts (even texts of proprietary licenses). Since NASA uses software licensed under the above licenses, and nobody has sued them, I doubt that this is going to be a huge legal problem. Not to mention if it ever went to court, the context of the time the license was written would be considered, and the term "worldwide" would likely be considered identical to "universal".
> * Also, I’m not sure all contributors would be happy if they moved to a license analogous to the GPL (that would mean users combining openStreetMap data with their own data would have to release their data under a similar license)*
Ummm... the OSM licence is very close to that already. It has a share-alike part, and most of the members are very much in favour of that....
There is now a Contributor Terms¹ which governs how the licence can be changed. It requires a two thirds majority of active contributors (at least one change in at least 3 of the last 12 months, a working email address and replies to an email within 3 weeks) to approve a change to an "other free and open licence".
That's a good way to change licences like that.
[1] https://wiki.osmfoundation.org/wiki/Licence/Contributor_Term...