I wonder can you tell me how is developed map application like on this site? http://www.streetdirectory.com
What API is used?
You can use the Streetdirectory API
"The easiest way to start learning about the SD Maps API is to see a simple example. The following web page displays a map centered on Streetdirectory Singapore Office, 305 Alexandra Road, Vantage Automotive Centre, Singapore 159942: "
Note: This is SD Map API which similar to Google Map API: