GnuCash

If you can't figure out where all the money you use every month goes, GnuCash is the tool that will let you manage your income much more efficiently.

This open source code is designed to manage the finances of a family or small business.

GnuCash uses a double entry accounting system and has an income/expenses account where you'll be able write down all of your financial operations.

It also lets you manage clients, suppliers, and employees; it supports operations in different currencies and lets you import files in QIF and OFX format.

Other interesting features on GnuCash include the following:
-Large variety of graphs and reports to summarize your financial activity.
-Transactions finder and scheduler.
-Bill due date reminders, and much more.