Last week I made new releases of PleiadesGeocoder and PleiadesOpenLayers, the software that's providing the geo capabilities of the Pleiades Beta portal. I haven't been doing the best job of explaining the software, and people -- particularly those familiar with byzantine open source GIS software -- may have misconceptions about the complexity of these Plone products. This stuff is dirt simple. PleiadesGeocoder (soon to be renamed to PleiadesGeo) allows you to annotate Plone content with georeferencing, and provides XML feed-like views of that content for consumption by geographic and mapping applications. The geo-annotations are inspired by EasyCommenting and PloneGoogleMaps (two interesting projects in their own rights), but the views are original.
What makes it all hang together? Reliable Zope 3 machinery and standards. The Pleiades products use Five, so configuring the geo-annotation of your custom content types is only a matter of adapting to IGeoItemSimple and registering your adapter with ZCML. KML and GeoRSS aren't my favorite languages in the world, but they certainly have momentum and plenty of application support. Combining GeoRSS with Atom works well for me, and will be fully supported in OpenLayers 2.2.