Wonderful WPF Apps : TrialBalance
TrialBalance is a free, shared-source accounting application that is designed to teach basic double-entry bookkeeping to High School and University students.
TrialBalance is not designed to run your business or to do your tax, although, if you knew enough about accounting, it could. TrialBalance simply provides a chart of accounts and allows you to record transactions against the five major account types - Assets, Liabilities, Revenue, Expenses and Equity
It is a work in progress at the moment, but it's a slick looking WPF Application
Nice one Paul