This book is designed as a complete programming guide to FEPI (Front End Programming Interface). FEPI is a forthcoming terminal emulatory of the CICS (Customer Information Control System) 3.3 environment, allowing users to write CICS application programs that communicate to various IBM systems running CICS, such as MVS and ESA. Taking a programming, rather than a reference, viewpoint, the book should enable senior designers and programmers to evaluate and make flexible use of FEPI.