RPG
RPG (Report Program Generator) is a high-level programming language primarily used for business applications on IBM midrange systems like the IBM i (formerly AS/400). It is designed for generating reports, processing data, and building enterprise-level applications with a focus on database integration and batch processing. RPG features a column-based syntax and strong support for IBM's DB2 database on the i platform.
Developers should learn RPG when working with legacy IBM i systems in industries like finance, manufacturing, or logistics, where it is widely used for maintaining and extending critical business applications. It is essential for roles involving IBM i administration, modernization projects (e.g., moving to RPG IV/free-format), or integrating with newer technologies like web services, as it offers deep access to system resources and database operations.