The Enterprise Server execution environment is built on top of the Micro Focus Enterprise Server technology that provides the infrastructure not just for executing COBOL, CICS, IMS, DB2, VSAM and JCL, but also for deploying existing transactions as Web Services for easier re-use within new SOA architectures like .NET and J2EE.
JCL applications written to run on a z/OS or VSE mainframe can be run with the Enterprise Server environment. You maintain the applications in the IDE.