Black Sheep Invoices is a free, GNU-licensed script for generating and managing invoices. The script is very customizable, allowing you to control every aspect of your invoices which can be downloaded in PDF format. We offer a free service for non-profit organizations who can log on and manage their invoices on our site. Alternatively, you can download a free GNU version which you can install on your own server. The site includes an online demo, installation instructions, contact information and more!