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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.

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.

InvoiceBerry is an online invoicing software for small businesses and freelancers. The software is web-based and was designed with simplicity and ease of use in mind. Businesses can create, send and manage their invoices and quotes from anywhere in the world. The software also provides an expense, payment and invoice reminder function.