Maps - old and new

I've come across a few good map websites in the last couple of weeks - some were posted in a thread on RMweb and I found a couple more too. Old OS Maps has maps from the 1940s with a google map overlay and links to other interesting map sites. New Popular Edition Maps has OS maps from the 1940s and is adding postcode data to them.

Web services company Fonant have produced this cool Full window map browser which demonstrates what can be dome with the OS OpenSpace API. Another website that uses this API is Where is the path? - which supports split screen mapping with OS maps (Current, 1930s and 1940s), Google Maps, Google Earth, OSM, OSM Cycle.  It doesn't support every possible combination but it does quite a lot. In single map mode it has handy arrows that point to magnetic north and true north and the google maps screens support Wikipedia and Panaramio layers. There are more OS OpenSpace projects in their gallery.