I now have a fully working Agas Map based on Open Layers. There's more that could be done, and I will revisit the pan/zoom functionality later, but the next job is the urgent replacement of the Google Maps feature with OSM. I've successfully tested an implementation of an OL map using the KML that we're currently generating, and I think that will be the way to approach it. It'll take some work. At present, the Icon style setting doesn't appear to be supported, although it is being retrieved. I think we'll need to override the styles from the KML, which will actually be nice because OL gives us more flexibility there. The other thing not yet working is the annotation popups, and that may have to be done in a different way.