TopTracker - Beautiful, free time tracking
GnuCash - A personal and small-business financial-accounting software, licensed under GNU/GPL and available for Linux, Windows, Mac OS X, BSD, and Solaris.
timeBuzzer - timeBuzzer enables freelancers and project-driven teams to track their time at the touch of a button, understand where their time goes and create reports with just a few clicks.
Ledger-cli.org - Ledger is a powerful, double-entry accounting system that is accessed from the UNIX command-line.
Cattr - Cattr is a free open-source self-hosted time tracker with desktop clients for windows, mac, linux.
Teamleader - CRM, invoicing & project planning in a single tool for SME's