Wii Device Library is a cross platform C# class library that provides an interface to various Wii related devices, like the Wiimote, Classic Controller, Nunchuk and Balance Board.

Features:

Supported Wii devices
– Wiimote
– Nunchuk
– Classic Controller
– Guitar
– Balance Board

Supported bluetooth stacks
– Microsoft bluetooth
– BlueSoleil
– BlueZ

Features
– A simple and intuitive programming interface.
– The ability to scan and connect to Wii devices.
– Wiimote extension support with a wide range of implemented extensions.
– Support for multiple stacks.
– The ability to extend the library to support more Wiimote extensions, devices and stacks.

http://wiibrew.org/wiki/Wii_Device_Library