This Map is based on Google Maps, and uses your vCard profile feeds to get the location. He says that in future he wants to use the XEPs XEP-0080 and XEP-0154 for the user location. This might be a project to keep an close eye on 😉
To use it, simply add email@example.com to your Jabber Roster. A few minutes later, you’ll find yourself on the Map.
Update: I was just told, that it is based on SleekXMPP.