In my opinion one of the top most API’s used globaly on web portals is Google Search API, Google is famous for building world class API’s to harness the unique data Google collected with it’s excellent set of technology.
Google Labs is the ultimate playground of Google which he use for developing and testing there upcoming API’s , They have some exciting set of API’s currently in building. Which promise better web and can provide better value than Google Maps and Google Search API’s
Virtual reality is the most discussed and researched technology few years back and it has proved it’s mark with the success of Second Life. O3D is natural extension to it and looks like it’s a extension to much hyped but failed technology VRML (Quotation needed)
Here’s a small example demo that is made using o3d Technology, Notice the amount of detail which goes in the demo video.
Google Wave API:-
Google Wave is another big collabration tool that Google is coming with, Aspired to be the next logical invention of Email . Google Wave innovates the collabration market with their wonderful approach of centric objects. Google Wave can be accessed via Google wave APi which can be integrated with applications for collabrtation . Google presented a keynote which presented some cool features of Google Wave
Developers can check out some cool wave applications at Wave Sample gallery and check out the technical documentation here , Unfortunately Google wave currently have only Client libraries for Python and Java , We look forward to the Php library from Google soon.
Google Gears and Adobe Air are two upcoming technologies that promise leveraging the power of desktop onto web , Google Gears API is a powerful tool for building web applications that can interact with the users desktops , Features like local caching, Storing user data locally and asynchronous threads are some powerful feature that can now be used on web apps.
Google Analytics API:- The most common tool that webmasters use is the analytics tool for their website and Google analytics is the ultimate data churning tool for any website, If used properly Analytics can dig down to the deepest point of the content and traffic coming on web app or portal.
Several mertrics system like Mint , Quantcast etc exist today and provides extensive data, But the google analytics api can prove to be a milestone in extracting and tracking the traffic details that can effect your ROI.
Google analytics documentation can be located here
Google Coupons:- Two words that bring maximum ROI in any form of business are FREE and SALE .
Coupons are one of the most searched terms on the web, Providing ecommerce users good discount on items, What could be better than the coupons data from the leader in data collection itself !, The coupons API !
Coupons API provide easy import to coupons data which can be used by business users, This is pretty same as the legendy google base tool which allow webmasters and business people to upload information about their product listing.
Coupons uploaded through coupon API will be indexed on google and will be presented to all users on searching for that product or relevant keywords.
It’s documentation can be found at this site
Hope you guys liked this list of API’s , Will love to listen your comments and any another set of API’s i missed.