1. A computer-implemented method for extending editing capability of a system editor executing on a digital computer, the system editor having a core set of commands, the method comprising the steps of: creating, in a high level programming language, a library separate from the system editor and core set of commands, the library containing at least one new editing command; and linking the system editor to the library to extend the editing capability of the system editor, wherein the high level programming language is one of ALGOL, C, COBOL, FORTRAN, and PASCAL.