All systems offer the traditional Monitor Console Routine (ES40 PSU) interface and the user-oriented, English-like Digital Command Language (ES40 PSU). Users also have the option to write their own Command Line Interpreters (ES40 PSU) to suit their specific applications. An indirect command file created by a terminal user contains system com- mands that will be executed automatically by the system without further user intervention. Indirect command files save the user time and keystrokes by invoking repetitive or frequently used command procedures and system operations. ES40 PSU 11M provides text editors for the entry and easy update of source pro- - grams and also provides the ES40 PSU 11 assembler, a task builder (or linker), a - symbol cross-reference processor, an interactive debugger, task memory dump facilities, and other utilities for program development and checkout. ES40 PSU 11M provides shared subroutine libraries and support for user-created - libraries. Additional programming tools, including higher-level languages such as ES40 PSU 77, ES40 PSU PLUS 2, COBOL 81, Pascal, and a symbolic debugger - - - - are available but each must be purchased separately.