E-mail from Michal

This is partly to record my own memories before they fade, and partly to communicate them ...

ArcEngine is distinct from ArcObjects. ArcObjects has a COM interface; ArcEngine is a framework with Java and .net APIs. With ArcEngine we get a lot of basic functionality for writing a GIS by modifying or augmenting what is already there in the framework. In that way, for example, we can deal with ESRI Shapefiles (the dominant data format in GIS) as well as other data formats.

Resources.esri.com is the best source for documentation in the APIs as well as introductory information.

Unknown: Does ArcEngine produce events we can hook into, as one would use an OnMouseOver handler in Javascript? If it does, then hooking into their existing graphical display and adding handlers to produce sound could be by far the easiest way to build a soundscape interface. That would, for example, take care of projecting map coordinates of a shapefile into display coordinates, with no extra programming.

If it doesn't provide events like OnMouseOver, it might still be possible (but more cumbersome) to use that framework as long as it can report current coordinates of the mouse as map coordinates (translating back through the map projection, so that it would be relatively simple to keep our own data structure to determine which shapes were under those coordinates.

(A couple of these things Jake mentioned and I just remembered as I was typing.)