There are different approaches to migrating CICS applications to a UNIX/Linux environment. The purpose of this section is to give an understanding not only of what CICS Runtime is and what it does, but also what it is not and what it does not do. Particularly the aim is to explain that CICS Runtime is not an emulation of the CICS application environment on a UNIX/Linux system. CICS Runtime keeps the application logic contained in the COBOL programs but is totally compatible with the Tuxedo client/server architecture for the execution of that logic. CICS Runtime provides a middleware between the CICS coding in the programs and the Tuxedo OLTP system, UNIX\Linux OS and Oracle database responsible for executing transactions and providing persistence.