EXHIBIT 21.01 IDT CORPORATION LIST OF SUBSIDIARIES IDT America, Corp. IDT International, Corp. IDT Internet Services, Inc. Internet Online Services, Inc. IDT Global Ltd. Media Response, Inc. Net2Phone, Inc. Rock Enterprises, Inc. Yovelle Renaissance Corporation Genie Interactive, Inc. InterExchange, Inc. Doublestone Computing Enterprises, Inc. Blue Sky Software, Inc. Altom Associates, Inc. Mikulynec Associates, Inc. Nuestra Voz Direct Inc. Union Telecard Alliance, LLC IDT Europe B.V. Forminto Ltd.