GnuCash Double-Entry Accounting Program.

You Need a Budget combines easy software with Four Simple Rules to help you quickly gain control of your money.

Moneydance is a personal finance software application.

Mint.com is a free, web-based personal financial management service.

HomeBank is a personal accounting software package that runs on OpenBSD, Linux, FreeBSD, Microsoft Windows, Mac OS (via macports or homebrew) and AmigaOS.