Microtonal musicians often lament the lack of support our art form receives from the companies that make electronic instruments. Some expensive keyboards offer retuning abilities. Even then, these capabilities are usually limited and impractical for more exotic tuning experiments. For example, they usually don't allow for keyboard mappings that are different from the normal twelve notes per octave.
The TBX tuning box from H-Pi Instruments provides a revolutionary solution to this problem. It allows you to change the tuning of standard MIDI keyboards in a very flexible manner. Check out the following video. It's a lot of fun to watch the improvisations in fifteen different tunings.
Tuning Box Demo