Runtime migration

Every COBOL program requires runtime library routines to execute. With the older compilers OS/VS COBOL and VS COBOL II, there was an option to have the runtime routines statically linked to the load modules (the NORES compiler option) or dynamically accessed at run time (the RES compiler option). Since COBOL/370 1.1 in 1991, all COBOL compilers default to the RES behavior.