QRCoder is a .NET class library that I wrote from scratch in C# and that allows the creation of QR codes. With over 4 million downloads of the associated Nuget package, the QRCoder is one of the most popular .NET libraries in its class.
The project arose in 2013 out of an interest in how QR codes work. And if you want to understand a software system, what could be more obvious than implementing it yourself?
QRCoder implements all essential functions of the QR code standard (ISO 18004). Further additional functions are planned for the future. The source code of the QRCoder is released under the MIT license and can therefore be used for non-commercial as well as commercial applications.