Slashgeo

The OpenGeoData blog made me aware of Mapstraction. The full introduction from the website: "Mapstraction is a library which provides a common API for Google, Yahoo! and Microsoft's javascript mapping APIs to enable switching from one to another as smoothly as possible. The aim of Mapstraction in mainly to protect companies building commercial products on top of Google Maps from changes to terms and conditions, the introduction of ads, or the emergence of a competing library with better maps, different imagery or preferable licensing terms. Mapstraction additionally fills some holes each provider's current offerings (taking advantage of existing open source solutions where possible) to normalise the feature set across platforms. In the future, Mapstraction will also talk to OpenStreetMap for people who want to build maps without restrictions on derived works."

All Points Blog offers an clear and to-the-point entry on the relationship between data and API licenses for webmapping apps, specifically Google, Microsoft, Yahoo! data into other webmapping apps such as OpenLayers. Meanwhile, The Earth is Square wonders if a workaround could revive a NASA World Wind plugin to access Google Maps data. From APB: "I had in my head that somehow OpenLayers was "doing something wrong" since it could pull in data sets from Google, Microsoft, Yahoo, MultiMap into its own interface (go play with that!). With quite a bit of patience Frank explained that OpenLayer is doing everything correctly. It has an API key for each of the API providers (if needed) and follows all the rules of the license. So, how is this different from the Gaia team noted above that got shut down? That group was accessing the data directly from Google servers and not, as stipulated in the license, via Google software. (Google Earth has no API like Google Maps does.) Frank even showed me the code where OpenLayers dutifully uses its API key to pull in tiles from Google Maps. Google, he noted, even contacted the MetaCarta team to ask if there was any thing needed to further their implementation!"

On his blog Niall Kennedy, compares three publicly available mapping APIs and demonstrates that "Yahoo! offered the fastest performance, the smallest total download, and the smallest memory footprint." Update: 08/08 21:01 GMT by S : All Points Blog adds a recent post on the Google Maps API vs Yahoo! Maps API.