This C++ library for Windows interfaces with the Bloomberg API. The Bloomberg API provides free, unrestricted access to raw financial data on current market trades (either real-time or delayed), reference data on historical information, and records of intraday trading. As part of their Open Market Data Initiative the library is offered under a "free-use" license, which allows unrestricted access to the interface's header files, documentation, and programming examples. Extensive documentation, including code examples, is available in the Developer Documentation and at the API website.
PollDaddy, one of the most popular online poll and survey creation services, recently opened their new API to the public. The basic PollDaddy service provides free accounts for creating polls and surveys, or a Pro upgrade that eliminates sponsored links and allows higher numbers of survey responses than the free version. Now with the API, the core poll creation and reporting services are available to developers (details at our PollDaddy API profile).
Microsoft's latest version of its search API (our Live Search API Profile), which was released last November as a public beta, seems to be gaining quite a bit of momentum. According to a recent post on the Live Search Blog, the API is serving more than 3 billion queries per month, more than 5,000 applications to use the API, and queries from third party sites account for 80% of the API's query volume.