[OSM-dev] Data format for OSM annotation layers

[Nick Whitelegg]

Hello Dan,

>> Those of you following the Freemap project will know that it includes 
an
>> annotation markers layer. It would seem to be a good idea to try and 
develop
>> an annotations data format which could be used by OSM mashups in 
general, and
>> develop an OpenLayers layer for it so that OSM mashups could easily use 
it.
>> Maybe we could just use KML? (I take it that wouldn't violate any 
Google
>> copyright issues?)

>GeoRSS would be perfect for this, wouldn't it? Then you could allow
>people to subscribe to updates in their area, and it'd be very
>portable and could be used on many different systems. I'd say KML
>would be a good addition to a GeoRSS feed, especially as Google
>Earth/Maps seem to be resisting GeoRSS so far.

My understanding of GeoRSS is that it is basically a geo-coded RSS format, 
i.e. it's good for (as you say) alerting people of updates on a map. 
However it doesn't really seem to be designed for bounding-box retrieval. 
The sort of app I had in mind involves the user panning an OSM slippy map 
and markers appearing as you move into new areas. Such an app would 
require a server which takes a bounding box and returns data of some sort 
representing the markers within.

There's no reason why GeoRSS cannot be used as the data format, I guess, 
other than (from my understanding) it wasn't designed for this type of 
scenario.

Nick