REXX command environments that are currently available (to use with the REXX ADDRESS command) are REXXCICS, CICS, EXECSQL, EDITSVR, FLSTSVR, RFS and RLS.
Support is provided for allowing new REXX/CICS commands and command environments to be dynamically defined. New commands may be written in REXX or in any REXX/CICS supported language (for example: Assembler, COBOL, C, PL/I). For more information on how commands and command environments are defined to REXX/CICS, see REXX/CICS Command Definition.