Optical keyboards are still around (although rare) and usually use some variation of Cherry MC style switches without contact pins. Newer tech also consists of

Optical keyboards are still around (although rare) and usually use some variation of Cherry MC style switches without contact pins. Newer tech also consists of magnetic designs (hall effect, tunnelmagnetoresistance or inductive). These all allow for analog input (variable user-settable actuation points for example) which makes them popular with the gaming crowd. I'm developing such a PCB for a different project at the moment. As far as I'm aware none of these are waterproof, however, as they all have exposed PCBs inside the case. I guess one could just conformally coat the circuit board, but I haven't seen that done yet for a commercial keyboard.