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

Expensify - Import expenses directly from a credit card to create free expense reports quickly. Approve reports online and reimburse directly to a checking account with one click.

YouNeedABudget - Personal home budget software built with Four Simple Rules to help you quickly gain control of your money, get out of debt, and reach your financial goals!

Abacus - Expenses without the 'expense report'

Grisbi - Accounting for everyone !

Zoho Expense - Automate your expense reporting process and streamline the approval flow.