They use special "upper" and "lower" layer keys to switch between mappings. There's a whole open source ecosystem around a project called QMK firmware, and conv

They use special "upper" and "lower" layer keys to switch between mappings. There's a whole open source ecosystem around a project called QMK firmware, and convergent common keymaps for keyboards that use it. 1: https://github.com/qmk/qmk_firmware https://github.com/qmk/qmk_firmware