using the wiimote as joystick/mouse for openmsx under linux

You will need a working bluetooth system on your PC or laptop. I won't describe how to do that :)

cwiid

This is a library for wii interfacing via bluetooth. It allows to map wii axes and buttons on the X mouse or buttons via a userspace input driver called "wminput". This driver is controlled via a simple configuration file. It works with a set of plugins that provide various forms of translation of wii bluetooth events to axes and key/button events.

1) wiimote sends  an event via bluetooth
2) a wminput plugin (as configured in the config file) handles the event and translates it to an axis or button/key event
3) the config file specifies how to map this axis or key on a mouse or joystick or button