Modest Maps features a simple interface with stuff like touch controls for mobile devices, fullscreen mode, a nice point-selector, a zoombox and more.
Unfortunately, Modest Maps can currently show only one layer, unlike OpenLayers. That’s why I especially like the combination with Leaflet. This allows layering and more of the functionality found in OpenLayers. Have a look at the demo, and try zooming on the map. It’s feels as smooth as some of the Silverlight demos I’ve seen.
So Wax integrates and extends several pieces of mapping software. Highly recommended for use when OpenLayers is deemed too heavy.