Corduroy (http://corduroysite.com/ http://corduroysite.com/) is a full billing system that includes time tracking for projects and invoicing. Some of its other

Corduroy (http://corduroysite.com/ http://corduroysite.com/) is a full billing system that includes time tracking for projects and invoicing. Some of its other features include interaction with your online banking site and allowing your customers to login to your site and pay their invoices with a credit card. Disclaimer: I am the author of it.