Journal of Engineering and Applied Sciences Technology

Legacy mainframe programming languages have been foundational in the development and operation of large-scale business and scientific computing systems since the mid-20th century. These languages, including COBOL, Assembler, PL/I, FORTRAN, RPG, JCL, ALGOL, Natural, CLIST, and REXX, were designed to handle the robust data processing needs of enterprises and government institutions. COBOL, known for its English-like syntax, is still widely used in business applications, while Assembler offers low-level hardware control for highly efficient execution. PL/I and FORTRAN cater to both business data processing and scientific computations, respectively. RPG, originally created for report generation, evolved to support comprehensive data processing tasks. JCL, although a scripting language rather than a programming language, is crucial for job execution in batch processing environments on IBM mainframes. ALGOL has been influential in the development of many modern languages. Natural and REXX facilitate rapid application development and scripting, respectively. Despite the emergence of modern programming languages, these legacy languages remain vital for maintaining and understanding existing mainframe systems, underscoring their enduring significance in the history of computing.