WiimoteLib is a .NET managed library for using a Nintendo Wii Remote (Wiimote) and extension controllers from a .NET application. Below are the important links needed to get started with the library.
The latest version is always available at GitHub. Click the link above and select the Releases tab for access to the library and source code
This library started out as an article at the Coding4Fun site. The article is a great starting point to learn how to use the library as well as to learn how it was written.