GnuCash is open source personal and small-business financial accounting software. Keep track of income and expenses from all of your accounts. The small-business features allow you to keep track of customers, vendors and projects - and helps you with invoicing as well as accounts receivable and accounts payable. With support for OFX DirectConnect and HBCI - GnuCash can even communicate with your bank, etc. if they support these standards. Everything including your investments can be extracted into reports and even presented as graphs.
Switching to GnuCash from other accounting software is also easy since it is able to import from both Microsoft Money and Quicken. Finally GnuCash is available in 29 languages to make sure you feel at home and understand exactly what is going on