The C/C++ library for Linux is for use 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. Note that the Linux libraries can only be used with the Bloomberg Server API and B-Pipe data feed products, and are not available for desktop API users.
How much will it cost to hire that cabbie? The Yourtaximeter API gives access to such precise data that cab companies in the UK rely on it to give quotes. Yourtaximeter provides a tool anyone can use to calculate a fare. The API documentation, other than providing a link to where you can get an access key and noting responses are flexibly delivered in JSON or XML, is rather skimpy. That's actually a complement: minimal documentation reflects the fact that no coding skills are required.
The key to any transaction whether in the online or physical world is the payment process. Payment is a common feature across desktop, web and mobile applications. PayPal is often the first choice that springs up on developers when they think of integrating payment into their applications. Developers want an easy to use API, sandbox testing, fair transaction fees and definitely less paperwork and wait time. Stripe aims to simplify the process of accepting payments on the Web with its easy-to-use Stripe API.