Richard Fairhurst <richard <at> systemed.net> writes: >Under CC-BY-SA, as I'm sure you know, a printed map can only be >licensed as copyleft. The cartographer therefore no longer has >exclusive rights to their "added value" (colours, selection of data to >include, and so on), which are clearly apparent from the map. These >can be trivially copied. > >Under CC-BY-SA, a routing service does not have to be licensed as >copyleft.[1] The author of the routing service does not have to >disclose their "added value" (weightings for different types of road, >any transformations applied to the data, etc.). These cannot be >trivially copied: to do so would require reverse-engineering a >near-infinite set of requests and you'd probably be banned for DoSing >before that. ;)
>But I don't see how arguing for full disclosure by cartographers, but >not by routing system authors, is tenable. What you wrote above is a very good argument for it. Rendering the data into a printed map is not a great deal of effort. Anyone can do it and many already do so. There are not many people who would be put off from rendering maps by being unable to make the result proprietary. The copyleft requirement is pretty trivial and doesn't create disincentives to rendering a map, because rendering a map is so easy. (In any case, even though you can freely copy a PNG file of a map or photocopy a page, and even though you can see for yourself what colour scheme was used, you don't have the program code that was used to render the ways and the text, which is the hard part. That code doesn't have to be distributed.) On the other hand, the data for a routing service such as road weightings takes a bit of effort to get right and is something that many companies wish to keep secret (while nobody thinks that map coloration can be a secret). If using OSM data meant you also had to reveal your routing database, it might act as a serious brake on use of OSM by the commercial routing services, and perhaps even in academic projects. Tele Atlas are quite happy to license their data without insisting that you disclose your algorithms or weights, and if OSM ends up being more restrictive then the companies won't use it. No loss to them - only to us. I support the principle of copyleft, but it is important not to get too greedy. Just because some seeming bad use of the data can technically be prevented by a certain extra clause in the licence does not mean that it should be. -- Ed Avis <e...@waniasset.com> _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
