[OSM-talk] server migration update / license change

[Paul Norman]

> From: Richard Weait [mailto:richard at weait.com]
> Subject: Re: [OSM-talk] server migration update / license change
> 
> On Thu, Apr 5, 2012 at 4:07 PM, Paul Norman <penorman at mac.com> wrote:
> > If the tiles are not regenerated then they will contain elements that
> > are licensed as cc by-sa only.
> 
> "Old tiles", the tiles generated at osm.org right now, are created from
> a CC-By-SA data base and are CC-By-SA tiles.  No problem.
> 
> > If you mix cc by-sa data with other data, doesn't this mean that the
> > entire work is only available as cc by-sa?
> 
> No.  You can, and some have, published All Rights Reserved C books with
> CC-By-SA OSM map images included.  No problem there.
> 
> In the case of osm.org tiles, there is even less of a problem.
> 1) "Old tiles", the current ones, are ccbysa from a ccbysa data base.
> That's fine.
> 2) "Future tiles", after the license switch is thrown, will be ccbysa
> from an ODbL data base.  That's fine.
> 3) The Collective Work [1] of "old tiles" and "future tiles" in the
> OpenLayers frame on osm.org will also be CC-By-SA.
> 
> So I don't see where there would be a licensing concern.
> 
> There IS a "mapper concern."  We'd like to keep the tiles fresh,
> wouldn't we?  So updating cached tiles after any update is something
> that we all like to see.  But I don't see a licensing concern here.
> :-)
> 
> [1] term from CC-By-SA for combining separate works.  In this case, each
> tile is a separate work.

If you start having some tiles where the produced work is CC by-sa with the
underlying data also cc by-sa and some where the produced work is cc by-sa
with the underlying data ODbL, how do you do attribution for each tile
differently?