# RPG/400

> programming language

**Wikidata**: [Q28942577](https://www.wikidata.org/wiki/Q28942577)  
**Source**: https://4ort.xyz/entity/rpg-400

## Summary
RPG/400 is a programming language developed by IBM, specifically designed for business applications on IBM midrange computers. It evolved from the original RPG language, which debuted in 1959, and was tailored for use on IBM's AS/400 systems starting in 1988. RPG/400 is known for its ease of use in file handling and report generation.

## Key Facts
- Inception: 1988
- Instance of: Programming language
- Influenced by: RPG (1959)
- Developer: IBM
- Platform: IBM AS/400 (now IBM i)
- Category: Business-oriented programming language
- Wikidata description: Programming language

## FAQs
### Q: What is RPG/400 used for?
A: RPG/400 is used for developing business applications, particularly on IBM's AS/400 systems. It excels in data processing, file handling, and generating reports, making it popular in enterprise environments.

### Q: How is RPG/400 related to RPG?
A: RPG/400 is a version of the RPG programming language adapted for the IBM AS/400 platform. It builds upon the syntax and structure of the original RPG language, which was introduced in 1959.

### Q: Is RPG/400 still in use today?
A: Yes, RPG/400 and its successors like RPG IV and Free Format RPG continue to be used in legacy systems, especially within industries such as finance, manufacturing, and logistics that rely on IBM i platforms.

## Why It Matters
RPG/400 plays a critical role in maintaining and evolving decades-old business-critical applications that run on IBM’s midrange computing systems. Many large enterprises depend on these systems for core operations, including inventory management, financial processing, and customer data handling. Its longevity underscores its reliability and integration depth within enterprise IT infrastructures. As organizations modernize, understanding RPG/400 remains essential for system interoperability and migration strategies.

## Notable For
- Designed specifically for IBM AS/400 systems
- Evolution from the historic RPG language (1959)
- Strong support for business data processing tasks
- Longevity and continued use in enterprise environments
- Integration with IBM i operating system features

## Body
### Origins and Development
RPG/400 is derived from RPG (Report Program Generator), originally created by IBM in 1959 for use on punched card systems. The language was re-engineered and extended for the IBM System/38 and later the AS/400 when it launched in 1988. This adaptation allowed businesses to migrate existing RPG programs while taking advantage of newer hardware capabilities.

### Technical Characteristics
RPG/400 is optimized for sequential and direct file processing. It uses fixed-format syntax but has evolved over time to include more flexible coding styles. Key strengths include built-in database access, integrated debugging tools, and strong error-handling mechanisms. It supports both procedural and modular programming paradigms.

### Platform Specificity
The language runs natively on IBM's AS/400 line of computers, now branded as IBM Power Systems running IBM i (formerly OS/400). RPG/400 integrates tightly with the system's DB2 database and security models, offering performance benefits and simplified development workflows for business applications.

### Legacy and Modernization
Despite being decades old, RPG/400 continues to power mission-critical applications across multiple sectors. Organizations often maintain RPG-based systems due to their stability and cost of replacement. Newer versions like RPG IV and free-form RPG have modernized the syntax while preserving backward compatibility, allowing gradual evolution rather than full rewrites.