Different Types of Google AJAX APIs
Currently, there are nine Google AJAX APIs available for anyone to use. Briefly here's what each of these Google AJAX APIs do:
Google Maps API - If you've edited a map using Google Maps, you can easily add it to your website using this API.
Google AJAX Search API - Allows you to embed Google Search to your website including Video, Local and News Search verticals
Google Visualization API - This API allows you to create visualizations and reporting applications by accessing structured data using a common format.
AJAX Libraries API - Lets you access popular AJAX libraries from Google's servers.
Google Book Search APIs - Another useful AJAX API, this time for integrating Google Book Search and Preview
Google Earth API - Similar to Google Maps API, this one lets you integrate Google Earth to your sites.
Google Friend Connect APIs - For social networking purposes, this API allows you to integrate social flows and data directly within your website's markup.