The Invoicer is a powerful and intuitive billing and invoicing system designed in PHP for the small professional that wants to use the power of the Internet to invoice clients. Allows your clients to pay via Paypal (full IPN support)! Other cart integrations can be requested. If features full administrative controls, email invoicing, template-based structure, client login area, and a full, flexible SQL-based database handled thru adoDB to permit easy migration between MySQL, Oracle, MS SQL, SQL server and more.