The Howdy Glossary

RPG/400 (Report Program Generator) is a proprietary programming language developed by IBM for generating business applications on midrange systems like the System/3X and AS/400. Initially, it was designed to streamline report generation processes and evolved from handling punch cards to become a procedural language with both fixed and free formats. Over time, newer versions such as RPG II, RPG III (RPG/III), and RPG IV (ILE-RPG or ILE RPG) were released to adapt to changing programming paradigms and industry needs, ultimately enhancing modularity and aligning with modern structures.

In the realm of business application development on midrange systems, RPG/400 has faced competition from languages like COBOL and PL/I. COBOL is known for its readability in business applications, while PL/I is recognized for its versatility in various programming tasks. Despite this competition, RPG has maintained relevance through its specialized focus on report generation and continuous evolution into more modern versions like RPG IV. Features such as Free-Format RPG allow inline data definition with executable code in free-form expressions, offering greater flexibility compared to earlier iterations.

The specialized focus on report generation provides businesses an efficient tool for producing reports within IBM's midrange environments. The evolution into modern modular programming structures through versions like ILE-RPG allows developers to create sophisticated applications while maintaining ease of use. The introduction of Free-Format RPG further enhances flexibility by enabling inline data definitions alongside executable code in free-form expressions. These features make RPG a robust tool well-suited for programmers developing business applications within IBM's midrange systems environment.