CICS (Customer Information Control System) is a transaction server that runs primarily on IBM mainframe systems under z/OS or z/VSE. CICS on distributed platforms is called TXSeries and it is available on AIX, Windows, Solaris and HP-UX. CICS is also available on other operating systems, notably i5/OS, OS/2. The z/OS implementation, ie, CICS Transaction Server for z/OS is by far the most popular and significant. It is known foremost as a pseudo-conversational computer application.
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