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. This library, for use with Windows OS, allows users to interface with the API from within Java. As part of their Open Market Data Initiative both the API and library are offered under a "free-use" license, which allows unrestricted access to the interface's header files, along with documentation and programming examples. Extensive documentation, including code examples, is available in the Developer Documentation and at the API website.
Quandl Founder Tammer Kamel wants to create a new Wikipedia for Numeric Data. Quandl has built a sort of "universal data parser" which has thus far parsed about 2.8 million datasets without anything from any data publisher. As long as they spit out data somehow (excel, text file, blog post, xml, api, etc) the "Q-bot" can slurp it up. The result is quandl.com as sort of "search engine" for numerical data. Quandl's bot returns data in a totally standard format. The idea with Quandl is that you can find data fast, and it is ready to use.