A simple chord keyboard.
Chord keyboards are pretty neat. They’re smaller and more portable than conventional keyboards, they can be more ergonomic, and (legend has it) they allow faster typing. I’ve wanted to build one for a while, mostly just for the fun of it, but also because I want a tool for one-handed data entry. When I’m laying out a sketch in FreeCAD, for instance, I often find myself switching my right hand between the mouse, for manipulating lines, curves, constraints, etc., and the keyboard, for entering dimensions and pressing hotkeys. I though it would be cool to have a complete keyboard in my left hand, so I built chord.