SharpShell
Create Windows Shell Extensions using the .NET Framework
...The library abstracts many of the complexities of COM programming, making it more accessible to developers who are familiar with .NET. It includes templates and examples that help developers quickly get started with building shell extensions. SharpShell also provides tools for debugging and testing extensions, improving the development experience. It is widely used for creating custom integrations within the Windows Explorer environment. Overall, SharpShell simplifies the process of extending Windows functionality through managed code.