Please note this is not an exhaustive list. Thanks for the spark Jeanne K!

Quotable: “Digital maps provide amazing opportunities for integrating and displaying large sets of data and research in innovative and interactive ways and the world’s taking notice!” via Interactive Maps: Why They’re Awesome for Connecting the Dots | Information Space

Digital Libraries

• World Digital Library
• Brock University Map Library
• University of Toronto Map & Data Library
• Canadian Geographic: Mapping
• Harvard Map Collections Digital Maps
• American Memory LoC Maps Collection
• GRID-Arendal Maps & Graphics Library. Interactive maps bottom of page.

Visualize Interactive Maps

• The Top 20 Data Visualization Tools | Brian Suda | .net Magazine. Mapping tools are listed from 10-15.
• ChartsBin. Clickable world maps.
• GeoCommons. All about open analysis, data and maps.
• GunnMap 2. Map some world data then save to png or jpg.
• Google Fusion Tables. An experimental data visualization web application to gather, visualize, and share larger data tables.
• Kartograph. A simple and lightweight framework for building interactive map applications without Google Maps or any other mapping service.
• Leaflet. An open-source JavaScript library for mobile-friendly interactive maps.
• Mapize. Illustrate your data and create social maps.
• National Geographic MapMaker Interactive. Explore your world with map themes, data, and tools for customizing your map.
• Polymaps. A free JavaScript library for making dynamic, interactive maps in modern web browsers.
• StatPlanet. Customizable interactive maps.
• Unfolding. Create interactive maps and geovisualizations in Processing and Java.
• ViewShare. A free platform for generating and customizing views that allow users to experience your digital collections.

You may also like:

• Open Data Tools. Tools to explore, publish and share public datasets.
• Great tools for data visualization. | Idea.org

Attribution: Description snippets pulled from corresponding website’s about/summary/tagline.