Ratpoison is a simple Window Manager with no fat library dependencies, no fancy graphics, no window decorations, and no rodent dependence
Save your carpals and reach typing guru status with your own keyboard layout, such as the fully optimized QGMLWB layout. Alternatively, use your power for evil and create a carpal-breaking TNWMLC layout to embarass office prima donnas and punish sluggish workers. And it's the only layout with its own line of Brazilian clothing.
Next is a keyboard-oriented, extensible web-browser designed for power users. The application has familiar key-bindings (Emacs, VI), is fully configurable and extensible in Lisp, and has powerful features for productive professionals.
Multiple Keyboards stuff
https://ice-wm.org/ (...with xinput library (maybe with Mate Desktop ;) )