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Quba Viewer, also known as Mustang Quba, is a free, open-source desktop application for creating, viewing, and validating electronic invoices. It focuses on ZUGFeRD and Factur-X invoices, which combine human-readable PDF documents with structured XML data. Users can import existing PDF invoices and enter the information required to generate compliant electronic invoices. The software also examines received invoices and identifies potential validation errors. It displays invoice details in a readable format alongside the original PDF and underlying XML. Validation can be performed offline using the Mustang Project libraries. Available for Windows, macOS, and Linux, Quba Viewer helps small businesses and accounting professionals manage standardized electronic invoicing.
Features
- ZUGFeRD and Factur-X electronic invoice creation from existing PDF documents
- Offline electronic invoice validation with detailed error reporting and diagnostics
- Side-by-side invoice PDF viewing and structured XML data inspection
- Invoice information entry for recipients, dates, line items, and billing details
- PDF/A-3 invoice generation with embedded machine-readable financial information
- Cross-platform desktop functionality for Windows, macOS, and Linux operating systems
Project Samples
