The rise of data mining, mobile applications and social media, among many others, has dramatically changed the face of Geographic Information Systems (GIS) and what they can accomplish. This has led to the creation of tools suited to various use cases. The most obvious place to begin when thinking about GIS is the web maps available through the Google Maps API.
However, in acknowledgement of GIS Day on November 19, Jason Baker wrote this article on opensource.com that describes three alternatives to the Google standard.
The library offered by Modest Maps is even smaller than Leaflet’s, but the modular design makes it a great way to create simple maps or select only the components relevant to each specific project, streamlining the development process.
It should be noted that neither Modest Maps nor Polymaps enjoy much active development, but both are still usable. The author suggests several other options that may be better suited depending on specific needs. The list of web mapping tools provided by the OpenGeo Foundation allows the mixing of mapping libraries, but careful attention must be paid to the scope and production-readiness of each tool.