If you have PL/I applications with ILC, move them to the Language Environment run time after you have converted each of the languages involved. For example, move a PL/I-COBOL application to Language Environment after you have moved your PL/I-only and COBOL-only applications to Language Environment.
After Language Environment has been installed in LNKLST, all of your PL/I applications will run under Language Environment by default.