What technology is available that allows third party software such as Mint.com, Microsoft Money or Quicken to connect to personal bank accounts. Do most banks offer an API or is there a standardized protocol and middle-tier service for accessing bank information? I’m interested in developing my own software and am trying to understand my options for connecting to bank accounts using customer login credentials.

I have used microsoft money and found the layout insanely frustrating. I am looking to have the capability to determine beta, alpha, volatility of individual investments and the portfolio as a whole. I would also like to be able to compare my returns to previous years and choose the time frame.
Thanks.
I fired my broker, because thats what he made me. And their portfolio tracking software was terrible. He had a 8 year time frame, and I wasn’t swapping in and out of things either.