Bloomberg Open API
This API has been available for a long time and enables to get access to market data (including live) if you are running a Bloomberg Terminal or have access to a Bloomberg Server, which is chargeable.
The only difference is that the API (not its code) has been open sourced, so it can now be used as a dependency in an open source project for example, without any copyrights issues, which was not the case before.
The API's will provide full access to LIVE data, and developers can thus provide applications and develop against the API without paying licencing fees. Consumers will pay for any data received from the apps provided by third party developers, and so BB will grow their audience and revenue in that way.
NOTE: Bloomberg is offering this programming interface (BLPAPI) under a free-use license. This license does not include nor provide access to any Bloomberg data or content.
Source: http://www.openbloomberg.com/open-api/
Since the data is not free, you can use this Bloomberg API Emulator (disclaimer: it's my project) to learn how to send requests and make subscriptions. This emulator looks and acts just like the real Bloomberg API, although it doesn't return real data. In my time developing applications that use the Bloomberg API, I rarely care about the actual data that I'm handling; I care about how to retrieve data.
If you want to learn how to use the Bloomberg API give it a try. If you want to test out your code without an account, use this. A Bloomberg account costs about $2,000 a month, so you can save a lot with this project.
The emulator now supports Java and C++ in addition to C#.
C#, C++, and Java:
- Intraday Tick Requests
- Intraday Bar Requests
- Reference Data Requests
- Historical Data Requests
- Market Data Subscriptions
Edit: Updated Project link, moved to github