GnuCash is personal and small-business financial-accounting software, freely licensed under the GNU GPL and available for GNU/Linux, BSD, Solaris, Mac OS X and Microsoft Windows.

Designed to be easy to use, yet powerful and flexible, GnuCash allows you to track bank accounts, stocks, income and expenses. As quick and intuitive to use as a checkbook register, it is based on professional accounting principles to ensure balanced books and accurate reports.
Feature Highlights

• Double-Entry Accounting
• Stock/Bond/Mutual Fund Accounts
• Small-Business Accounting
• Customers, Vendors, Jobs, Invoices, A/P, A/R
• QIF/OFX/HBCI Import, Transaction Matching
• Reports, Graphs
• Scheduled Transactions
• Financial Calculations