Optimus Maximus with complete functionality has a screen in each key that displays the function currently assigned to it. Keyboards with passive keys can be upgraded with active keys at any time. Say, if you bought a keyboard that has 10 active keys, you can buy however more active keys you need and have them installed. Optimus Maximus’s customizable layout allows convenient use of any language—Cyrillic, Ancient Greek, Georgian, Arabic, Quenya, hiragana, etc.—as well as of any other character sets: notes, numerals, special symbols, HTML codes, math functions and so on to infinity.  Any key (or to be exact, a unit consisting of a cap, a microchip and a display) can be easily removed by hands to be cleaned or replaced. Optimus Configurator software allows programming every button to reproduce a sequence of symbols and editing the image separately for each layout. Source : http://store.artlebedev.com