This project, based on OpenStreetMap, looks great:
OpenFreeMap lets you display custom maps on your website and apps for free.
You can either self-host or use our public instance.
I’m going to try it out on The Session once there’s documentation for using this with Leaflet.
Testing James Joyce: this is like the Seven Bridges of Königsberg puzzle but with Guinness.
Nifty old-school 8-bit tiles superimposed on OpenStreetMap data.
This is wonderful: maps that travel from the internet to the papernet and back to the internet again. Print out from OpenStreetMap, annotate in the real world, and scan the annotated map.