For use in Windows, this Java library 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.
Intuit QuickBooks may be the most popular financial software in the United States--one consulting firm reports that Intuit's accounting and tax programs control more than 90% retail market share--but the company has struggled with moving its desktop-based software into the cloud. Sure, there's an API for QuickBooks Online, but what about the many offline users who continue to rely on the finicky helper program QuickBooks Web Connector?