The Community Exchange System (CES) is an initiative of SANE (South African New Economics Network), and comprises a number of community-based international trading networks using a money other than our familiar national one — an alternative, parallel or complementary currency system. From child care to karate lessons to phone companionship, to computer programming and gardening, there's no limit to the ways of earning money in this system. In this way a community currency acts like a supplementary currency, creating an additional stream of value in a community. By supplementing conventional cash flow with a local currency, a community can maintain full employment and protect itself from changes and fluctuations in the national money supply.