Yodlee is the leader.<p>There's an old OSS code base that may (?) be useful.<p><a href="http://blog.precipice.org/why-wesabe-lost-to-mint/" rel="nofollow">http://blog.precipice.org/why-wesabe-lost-to-mint/</a><p><a href="http://readwrite.com/2011/02/25/crawl-your-bank-account-with-w" rel="nofollow">http://readwrite.com/2011/02/25/crawl-your-bank-account-with...</a><p><a href="https://github.com/wesabe" rel="nofollow">https://github.com/wesabe</a>