Here's a guest post we wrote for the Cesium blog, here's a link to the full article:
Web developers who are evaluating alternatives to the Google Earth API should look to Cesium for ease of use, impressive visualization capability and broad compatibility with WebGL. Former Google Earth developers will quickly be impressed with Cesium's power & stability, rich API reference and relative ease in migrating code. This article provides some background on what the Google Earth API contributed to 3D mapping and information for developers on what to expect when planning a migration to Cesium. (continue)