[Osmf-talk] CC BY SA 2.0 and backup plan

[Matt Amos]

80n wrote:
> On Sat, Dec 5, 2009 at 2:23 PM, Matt Amos <matt at asklater.com 
> <mailto:matt at asklater.com>> wrote:
> 
>     Jeroen Carelse wrote:
>      > I read the CC BY SA 2.0 under which the current data seems to be
>     licensed.
>      > Based on my understanding I would be allowed to download all the
>     data, put it on my server and use it under the  CC BY SA 2.0 stated
>     conditions.
>      >
>      > I could in that case keep it as it is or perhaps start alt-OSM
>     v3.0 ( to name something).
>      >
>      > In this way the current data would be safe guarded from, if any,
>     possible disruptions or "white spots".
>      >
>      > What is wrong in my reasoning?
> 
>     nothing. we will be providing a "full history planet" at the last point
>     before the changeover itself to ensure that all data contributed under
>     CC BY-SA is available. all previous planet files will, of course,
>     continue to be CC BY-SA licensed.
> 
>     i think it would be good to have this hosted on a read-only server
>     somewhere, as there may be people who change their mind post-vote and
>     need to "recover" their contributions. this process would be helped by 
> 
>     making access to the old contributions easier.
> 
> 
> It should be pointed out however that you would not be allowed to 
> combine the CC-BY-SA planet file with new ODbL licensed data and publish 
> a map from it.
> 
> ODbL and CC-BY-SA are incompatible and you cannot publish anything that 
> contains a mixture of the two.

that's not the full story: you can't publish a map based on a derivative 
  of both the CC BY-SA data and ODbL**.

you probably *can* publish a map based on a collective database of CC 
BY-SA data and ODbL data, and the produced work will be CC BY-SA licensed.

i think you *can* publish a map based on a collective database of CC 
BY-SA data and a derivative of ODbL data, and the produced work will be 
CC BY-SA licensed and the whole dump, or diff, of the derivative ODbL 
data must be available.

i think you *can* publish a map based on a collective database of CC 
BY-SA derivative data and a derivative of ODbL data as long as the 
derivative doesn't "represent, in terms of obtaining, verification or 
presentation, significant investment", and the produced work is CC 
BY-SA, and the diff/dump of the ODbL data is made available.

cheers,

matt

** except if you're willing to state that CC BY-SA simply doesn't apply 
to factual data, in which case you could get away with it.