L-system

plural of management system

(management) A computer software system for organizing and facilitating collaborative creation of documents and other content, especially for loading to a website

plural of adversarial system

(physiology) The circulatory system.

A voting system.

plural of electoral system

(education, historical) The system of home study established in connection with the summer schools assembled at Chautauqua, New York, by the Methodist Episcopal bishop John Heyl Vincent.

(historical) A haulage system for canal boats, in which an electric locomotive running on a monorail has its adhesion materially increased by the pull of the tow rope on a series of inclined gripping wheels.

(historical) A system used by the US Navy in the late 19th century to enable ship-to-ship communications at night. Each installation used a series of eight double lamps (four red and four white) hung from a mast and used to transmit visual codes.