Javascript for draggable, zoomable map with Google-Maps-like features

Question

I'm looking for a JavaScript-based tool for displaying draggable, zoomable maps. It has to have the following features:

• Can add markers, labels, balloons (a la Google maps)
• Must be scriptable after creation (so I can add or update content on the fly)
• must work offline
• must scale to the browser size (specifically, it must be mobile friendly)

Ideally, pure JavaScript or based on the jQuery framework. I'd rather not have to have competing frameworks on a single page.

Answer 1

Looks like OpenLayers does what I want. I'll update this answer if I run into problems with it.