Customer Information Control System (CICS) ist ein TP-Monitor für Hostsysteme von der Firma IBM. IBM’s general-purpose online transaction processing (OLTP) software is an e-business, industrial-strength, server for mission-critical applications. CICS is a powerful application server that runs on S/390 servers and a range of other operating systems, IBM and non-IBM, from the smallest desktop to the largest mainframe. It is used in Client/Server environments and in networks ranging in size from a few terminals to many thousands of terminals. It is a layer of middleware that seamlessly integrates all the basic software services required by OLTP applications.