HousingMaps was the first to reverse engineer Google Maps, which helped Google realize the potential of an API and motivate them to make it a real thing. That A

HousingMaps was the first to reverse engineer Google Maps, which helped Google realize the potential of an API and motivate them to make it a real thing. That API was one of the first very popular JS APIs on the web (it was #1 on programmableweb.com for years), and may have been many developer's first introduction to AJAX(JSONP) based APIs/UIs. (I worked on the Maps API for 4 years, so that's based on what I remember).