Bookyt is a bookkeeping/ERP application designed for small-to-medium-sized companies. It can handle debit invoices, credit invoices, projects with timelogs, swiss salary management, and much more.
CyDoc is a Web-based doctor's office application. It allows you to track your patients' medical history and handles all your billing needs.
A easy-to-use .NET IRC client library.
A dynamic scaffolding application framework in PHP.