German (mainly Knig) and Jewish (Ashkenazic; also Knig): from Middle High German knic German Knig 'king' hence a German nickname for a servant or retainer of a king (for example a farmer on a royal demesne) or alternatively a status name for the head of a craftmen's guild or a society of sharpshooters or minstrels.
The Call of Duty series has used a variety of programming languages over the years, including C, C++, and scripting languages such as Lua for game logic. Different games in the series may have used different languages depending on the specific requirements of each game.