DotNetInvoice is a complete invoice and billing system, specifically designed for web design and web development companies to bill their clients. It supports both Authorize.Net and PayPal.
Developer: DotNetInvoice Platform: windows Date upd:2005-05-02 Hits1107 [Visit]

XSE.NET is an electronic commerce software built upon the Microsoft .Net framework providing a complete shopping cart system. The application includes dynamically driven menus, optimized search function, Web Based Administration Control Center and search engine optimization. Customizable templates provide extensive flexibility in site design.
Developer: IQservices.com Platform: windows Date upd:2005-01-22 Hits5027 [Download] [Visit]

includes shopping cart, admin panel to add delete items, categories, very basic and easy to install
Developer: EMiN3M Platform: linux, windows, freebsd Date upd:2007-06-03 Hits143 [Download] [Visit]

byteCommerce for ASP.NET is an e-commerce module specifically tailored to sell digital goods of any type (shareware software, MP3s, videos, e-books etc.) with PayPal. Files are downloaded securely, and are tracked to avoid too much downloads. Features include a powerful reporting center, a professional
Developer: Intellibits Platform: windows Date upd:2007-05-09 Hits101 [Visit]

Own a hosting and domain registration company? Our domain cart application is designed to provide an online domain and hosting cart system that features full customisability, simple XML configuration, multiple hosting plans and TLD support for single and monthly payments. MD2 Domain Cart will
Developer: MD2 Software Platform: windows Date upd:2005-02-12 Hits1538 [Download] [Visit]