Too Long; Didn't Read
The Report Program Generator (or RPG for short) is a high-level programming language. It is an IBM proprietary programming module and can only be accessed on IBM i- or OS/400-based systems. RPG is still a popular programming language on the IBMi operating system. RPG IV (also known as ILE RPG) is the most current version of RPG and it is a tool that provides a highly enabling programming environment for AS400 RPG Programmers. RPG has been the most reliable language for commercial applications.