# RPG IV

> programming language

**Wikidata**: [Q28942597](https://www.wikidata.org/wiki/Q28942597)  
**Source**: https://4ort.xyz/entity/rpg-iv

## Summary
RPG IV is a programming language developed by IBM, primarily used for business applications on IBM i (formerly AS/400) systems. It evolved from earlier versions of RPG, with RPG IV being introduced in 2001. The language supports both fixed-format and free-format syntax and remains widely used in enterprise environments for legacy system maintenance and modern application development.

## Key Facts
- Inception year: 2001
- Instance of: Programming language
- Influenced by: RPG (original version released in 1959)
- Developer: IBM
- Primary platform: IBM i (AS/400) systems
- Syntax formats supported: Fixed format and free format
- Part of the RPG family of languages

## FAQs
### Q: What is RPG IV used for?
A: RPG IV is primarily used for developing and maintaining business applications on IBM i systems. It's commonly found in enterprise resource planning (ERP), financial systems, and inventory management applications due to its strong integration with IBM's database technologies.

### Q: How does RPG IV differ from earlier RPG versions?
A: RPG IV introduced significant enhancements including support for free-format coding style, improved data types, better integration with SQL, and object-oriented programming features. These changes made the language more accessible to programmers familiar with other modern programming languages while preserving backward compatibility.

### Q: Is RPG IV still relevant today?
A: Yes, RPG IV continues to be actively used in many large enterprises, particularly those running IBM Power Systems. Many organizations maintain critical business operations on systems programmed in RPG IV, and IBM continues to update the language with new features ensuring its ongoing relevance in legacy system support and evolution.

## Why It Matters
RPG IV plays a crucial role in sustaining decades-old but mission-critical business systems across industries such as finance, manufacturing, and retail. As an evolution of one of the oldest high-level programming languages, RPG IV bridges the gap between legacy computing infrastructure and contemporary software practices. Its continued use reflects the reality that many core business processes rely on stable, proven technology stacks rather than frequent rewrites. Organizations utilizing RPG IV benefit from mature tooling, deep institutional knowledge, and robust performance within IBM’s integrated ecosystem. Understanding RPG IV is essential for IT professionals working with enterprise systems, especially during digital transformation initiatives involving legacy modernization or coexistence strategies.

## Notable For
- Being part of the long-standing RPG programming language lineage dating back to 1959
- Introducing free-format syntax alongside traditional fixed-format styles in 2001
- Maintaining backward compatibility with earlier RPG codebases
- Serving as the primary development language for IBM i (AS/400) platforms
- Supporting hybrid procedural and object-oriented paradigms tailored for business applications

## Body
### History and Development
RPG IV was introduced in 2001 as the fourth major iteration of IBM's Report Program Generator (RPG) language. It built upon the foundations laid by RPG III and incorporated feedback from decades of real-world usage in corporate computing environments. The release marked a pivotal shift toward modernizing the language without abandoning existing investments in prior versions.

### Technical Characteristics
The language combines procedural programming constructs with newer features like:
- Free-format syntax options
- Enhanced data typing capabilities
- Built-in functions for string manipulation and mathematical operations
- Integrated debugging tools
- Support for modular programming through subprocedures and service programs

### Platform Integration
RPG IV operates exclusively within IBM's midrange computing environment, specifically targeting IBM i operating systems running on Power Systems hardware. This tight coupling allows seamless interaction with DB2 for i databases, integrated security models, and job scheduling services native to the platform.

### Current Status and Usage
Despite perceptions of obsolescence, RPG IV remains integral to numerous Fortune 500 companies' backend operations. IBM regularly updates the language with enhancements aligned with current software trends, including web services connectivity, mobile backend support, and cloud-ready deployment models. Thousands of active developers worldwide continue using RPG IV for both greenfield projects and legacy system evolution.