Rocket Invoice!

InvoicePlane is a self-hosted open source application for managing your quotes, invoices, clients and payments. The application comes with various options, templates and settings to customize your invoicing experience.

BILLmanager is a linux-based control panel for automating client management, invoicing and billing. This software specifically developed for hosting service providers will help you manage and take complete control of various aspects of your business:

FusionInvoice is an open source invoicing, quotes, and client management application built for freelancers and small businesses who need a simple, yet powerful self-hosted web based invoicing system. FusionInvoice is community driven so ideas/features, help/support and more is all provided by the project developer and various dedicated Fi users.

Moon Invoice" is unique and 1st invoice app with iCloud sync for iOS and Mac OSX for small businesses and individual. You can Create invoices, estimates, purchase orders, customers, vendors and payment receipts etc

ERP32 is a business application available on the Internet, just like an online bank services or webmail. The program allows you to centrally manage business processes and is intended for small and medium enterprises up to 100 users.

BillGrid is an easy to use online invoicing, billing and expense management system that will save you time with tracking clients projects, expenses, invoices and payments.

Invoicera is an online billing software which is specifically designed keeping simplicity and online invoicing convenience in mind, while at the same time offering the best of the breed invoicing features.

Use this extremely small and lightweight project built in Angular JS to build your one off Invoices. No monthly fees, No Subscriptions - No heavy duty features, Just simple invoices.

Looking for an easy, self-service Invoice Manager to add an online invoicing and billing functionality to your e-commerce website? Stop and take a closer look at our PHP invoice script! The invoice system contains all must-have features you might need. If not, we can further upgrade its functionalities to meet your exact requirements. With our PHP billing software you can control all orders and invoices from a centralized admin area and manage your customer database online.