RPG

IBM's database development language or "Report Program Generator", the use of the full name is discouraged since the remit of the language has grown immensely since it was first conceived and is now a full programming language with emphasis on business applications. Best known as the main application development language behind the AS/400.

The main reason RPG lives on in the modern world is how well it is integrated into some IBM operating systems, particularly System i, but also that combined with available RAD tools it is a considerably more productive and less complex environment than the C++/Java + SQL + Application frameworks environments most people put forward as modern replacements. For OS/2 programming it is mostly dead however.

A list of OS/2 implementations of RPG

• Baby/36 - Commercial - Discontinued.
• Baby/38 - Commercial - Discontinued.
• Baby/400 - Commercial - Discontinued.
• Code/400 - Commercial - Discontinued
• IBM PS/2 RPG II Application Platform - Commercial - Discontinued
• VisualAge for RPG - Commercial - Discontinued

Foreign libraries with RPG bindings

• LibcURL - Internet URL (WWW, FTP, etc) access - Open Source - Current.

RPG related utilities and toolkits

• IBM PS/2 RPG II Application Platform - Commercial - Discontinued
• Visual Tools/400 - Commercial - Discontinued

Workframes and or IDE's

• IBM WorkFrame/2 - Supports Code/400 and older DOS tools - Commercial - Discontinued.

DOS implementations of RPG

(Commercial - Discontinued)

• Baby/36
• Baby/400
• IBM DOS RPG II
• Lattice RPG II
• Lattice RPG 400D
• PC RPG II

DOS RPG utilities

(Commercial - Discontinued)

• Lattice CodePRobe
• Lattice DFE/DFU

A list of RPG implementations and tools that run under WinOS/2

• Baby/36 - Commercial - Discontinued
• Baby/400 - Commercial - Discontinued
• Lattice RPG 400W - Commercial - Discontinued

RPG related utilities

• Visual Tools/400 - Commercial - Discontinued

Links & publications

• RPG logic flow
• Brian Kelly: RPG: A Great Language with a Greater History
• Jim Staton: Being a Better RPG Programmer - 2012
• Report Program Generator (RPG) Programming Reference Manual - From Unisys

Books

• Robert Cozzi: The Modern RPG IV Language 4th edition - 2006 - MC Press - ISBN 1583470646
• Robert Cozzi: Introduction to RPG - 1997 - MC Press - ISBN 1883884462
• Robert Cozzi: The Modern RPG Language: With Structured Programming - 1996 - MC Press - ISBN 0962182508

Introductory articles

• RPG - on America Pink

Mailing lists & forums

• RPG400-l - Dedicated to RPG on the System i, but amenable to answering other RPG related quaetions.

Tutorials and other learning material

• Jay Moseley's RGP II tutorial
• Enskill online RPG tutorials

RPG history

RPG was originally developed in 1959 as the Report Program Generator and was then a utility that replaced some of the punched card processing on the IBM 1401, RPG II was introduced for the IBM System/3 in the mid/late 1960s and had by that time started to resemble a programming language more. RPG IV was introduced on OS/2 and AS/400 in 1995.

RPG II

Introduced on IBM mainframe systems but was made famous when it was shipped with the IBM "small systems" System/3 and later with the incredibly popular System/34]] and System/36 but it also showed up on the relatively obscure System/32 PC, in modern IBM parlance these systems are now referred to not as small systems but as "midrange systems". Something like 80% of all software written for the System/3x machines was written in RPG II with the rest split between COBOL and object systems (effectively assembler).

RPG II is by far the most supported variant of the language as manufacturers like Unisys, DEC, GE and so on all made RPG II compatible system available on their mainframe and minicomputer systems and development systems were available for microcomputers running CP/M, DOS and OS/2. Even today you can get RGP II support for most mainframe and what remains of the minicomputer industry in addition to a number of UNIX systems, later variants are however only supported on IBM hardware with at few exception. But even IBM itself does not support RPG III or IV on mainframes, only RPG II is supported on modern Z/OS systems.