The Circonus Ruby SDK by David Nicklay allows API interaction. It includes methods to work with account, annotation, broker, user, and worksheet. Examples demonstrate how to obtain information from US brokers.
Structured data has an open platform, thanks to a new startup aptly named Factual. At first glance, it seems like Excel on the web. However, Factual is more database-oriented, with joining and filtering built-in. Plus, sharing and discussing the data is an integral part of the experience. Most functions on the site, including both reading and writing data, can also happen via the Factual API.
Waiters like to work in pricey restaurants serving wealthy patrons because they are able to pay for high class service. That's also why you see so many professionals in the banking industry: it pays to work for people with money. Xignite took note of this and decided to become the Maitre'd of information to the financial industry. With more than 3.5 Billion calls per month to its Xignite APIs, it is doing a fine job of it, as well.