The Dandelion Language Detection Curl Sample Code demonstrates how to interact with the Language Detection API that is a tool that may be useful when dealing with texts. It currently supports 96 languages.
As far as web search tools go, few have generated as much hype as Wolfram Alpha. The service, which bills itself as a "computational knowledge engine," differs from search engines such as Google, in that it does not return lists of web pages. Rather, Wolfram Alpha attempts to calculate answers to user queries. For example, a query of "los angeles county median household income" will return the result "$43,518."
Life on the web is full of search terms and human filtering. Even good results often require some effort to determine which has the information we seek. There are several services attempting to help with this problem and they're making their applications available via API.
While social networking sites already help users maintain connections with friends and interest groups, a recent trend in web services has been the growth of semantic technologies that connect people across different websites. New York startup AdaptiveBlue offer a service called "Glue," which uses semantic web techniques to understand the content of popular web pages that describe lifestyle objects such as books, music, and movies. It then lets you do many useful, in-context things based on that data, such as learn more about the movie or actors on IMDB, buy the soundtrack on Amazon, read the historical background on Wikipedia, and a interact with a variety of other sites and services.