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.
It's hard to get excited about developing applications if there's no payoff for your efforts. That's the general consensus arising among makers of Windows Phone applications, who are dissatisfied with the poor sell through of advertisements. With no money coming in from ads, some developers say they'll have to start charging for their apps - or quit supporting Windows Phone.