ZUGFeRD-csharp
ZUGFeRD-CSharp is an open-source C library designed to simplify the creation and processing of ZUGFeRD electronic invoices. Originally launched in 2013, it has become a production-grade tool relied upon by hundreds of companies. The project now operates under an open-core model: the core library remains open source with ongoing bug fixes and stability improvements, while new features and advanced functionality are reserved for the commercial version known as FactoorSharp. The commercial offering includes a robust validation component compatible with tools like Mustang, Valitool, and VeraPDF, early support for emerging e-invoicing standards, and access to professional support and online analysis services. This hybrid approach ensures that the existing community maintains a stable foundation for basic invoicing tasks while enabling enterprises that require extended capabilities, enhanced reliability, and forward compatibility to leverage the full power of the updated ecosystem. The library facilitates compliant