Mint - Free personal finance software to assist you to manage your money, financial planning, and budget planning tools. Achieve your financial goals with Mint.

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

Ledger-cli.org - Ledger is a powerful, double-entry accounting system that is accessed from the UNIX command-line.

Money Manager Ex - Money Manager Ex is a free, open-source, cross-platform, easy-to-use personal finance software.

Free Invoicing Software - Free Invoicing Software provides the facility of online billing.

Buxfer - Online tools for personal finance, budgeting, and bill reminders. Split bills and IOUs with friends and roommates.