Leaflet is an amazingly powerful tool. As others have mentioned, it makes it easy to use a variety of sources for the underlying map tiles; in my case I was able to replace the modern-day base map with a map of the Roman Empire for an interactive academic publication[1].

Another great feature that doesn't get as much attention is Leaflet's ability to handle non-geographic images. In the same publication I'm also using it as a general-purpose deep zoom viewer for displaying artifacts[2]. It's great to just use a single library to handle all of this.

Kudos to the Leaflet developers for continuing to improve such a great library!

[1]: http://www.getty.edu/publications/romanmosaics/catalogue/ita... [2]: http://www.getty.edu/publications/romanmosaics/catalogue/1/