That's a snapshot of the google maps application, with an info window that appears when a marker is clicked. It sends a GetFeatureInfo request back to a mapserver WMS.
Vector drawing in the browser is limited. The amazing efforts of the OpenLayers, featureserver projects make this difficult to assert, as they abstract away all of the browser incompatibilities and give a nice platform to do real vector editing in a map. Still, there's a limit, and even if browsers become twice as fast in the next 2-3 years (and that's a big if, because the slowest commonly used browser will be the weakest link), the limit will be at 1000 markers.
Flash is built to do vector drawing. It's cross-browser. I've got my toes wet with a flash-based project and now that I am passed (part of) the learning curve, I figured I'd see what's available for GIS applications in flash...
Yahoo fairly recently released their Actionscript 3.0 version of their maps API. The examples look very straight-forward, if a bit heavy on the under-scores--even for a pythonista. But it's not open source, and there is no indication on how one would request tiles from any source--say WMS.
I'm still looking at worldkit, and even provided a patch to allow it to compile with mtasc. The worldkit approach as I understand it is to just provide the functionality in the flash movie, and only offer customization through an inutitive config.xml file, so no actionscript programming is necessary. Of course, this isn't strictly the case, but I think it's the way that it's most used. It's licensed GPL...
Anyone know of any others? I guess my criteria are:
- Active, currently developed
- Open source
- WMS friendly
I was able to get a modestmaps actionscript 2.0 movie to show 2500 markers, with the map still very responsive. The as3 version should perform even better because a marker can be a subclass of the more lightweight Sprite, rather than the full movieclip.
this is a shot of the randomly placed markers.