June 17


What is the Best IBM i RPG Code Editor in 2021?

By NickLitten

June 17, 2021

Code Editor, AS400, IBM i on Power, IDE, iseries

What is the best ibm i rpg code editor in 2021? 1

The Winner is Visual Studio Code

Visual Studio Code is an IDE (Interactive Development Environment). It’s a modern coding tool helping software developers to work with many languages. To write and maintain source code on your IBM i, iSeries or AS400 system, simply download and install the ‘Code for IBM i’ addon. Visual Studio Code is the best IDE for extensibility, it works brilliantly and is FREE!

FREE COURSE — Upgrade from SEU to a Programming IDE

Modern IBM i professionals swear by the graphical IDE, particularly compared to older greenscreen coding environments like PDM and SEU. In this course we will cover all the main elements of using an IDE to write code in both RPGLE, CL, PF, LF , SQL, DSPF and PRTF and more.

What is the Best IBM i RPG Code Editor in 2021

Most people migrated from SEU to RDi (Rational Developer)

But there are other code editor choices out there, so let’s have a look at a few different options:

What is the best FREE RPG Code Editor?
What is the best PREMIUM RPG Editor?
What is the best Editor for RPG, CLP, DDS and SQL in 2021?
Ibm i rpg programmer

Back in the days of terminals, no internet and green screen access only – IBM’s native code edit SEU, in all its green screen 5250 glory, reigned supreme for decades.

Every IBM i programmer will be very familiar with SEU (Stoneage Editing Utility). Introduced nearly fifty years ago (doesn’t that make you feel old?) it was the standard code editor on the old AS400 and Series machines.

In 2008, with the launch of a major operating system upgrade (IBM i V6.1), IBM announced that support for the old SEU was being withdrawn: IBM wants people to adopt their flagship code editor for IBM i Software Developers — RDi is Rational Developer for i. But SEU still exists, is useable, but is no longer updated as new program language features are released. For a decade SEU’s syntax checking has been frozen at IBM V6, so trying to write modern IBM i code in SEU is a nightmare as it flags all these new features as errors.

IBM RDi is an Eclipse based code editor for IBM i Developers used for writing modern RPG, CL, XML, JAVA, PHP etc code. In earlier released Rational Developer was called WDSC “WebSphere Development Studio Client”. But with a complete rewrite of the IDE it was rebranded and re-released as RDi (Rational Developer for IBM i). If you are not using an IDE code editor then your developers are probably stuck with the twenty year old text based code editor SEU “Stoneage Editing Utility” 😉

There are various IBM i Code Editing Solutions ranging from opensource and freeware to modern commercial products.

So, in no particular order, let’s have a look at some of them:


What is the best ibm i rpg code editor in 2021? 2

SEU – IBM Source Entry Utility

The STRSEU (Source Entry Utility) command allows you to create, change, display, or print a source member.

I’ve called this *FREE* but it’s not really. You have to install the IBM Licensed Program. SEU is part of the IBM® Rational® Development Studio for i licensed program.

If you use SEU to enter source in a database file, SEU adds the sequence number and date fields to each source record. You can edit, delete and add records between existing records. For example, if you add a record between records 0003.00 and 0004.00, the sequence number of the added record can be 0003.01. SEU will automatically arrange the newly added statements in this way

Sadly, SEU was frozen and IBM ended all enhancements over a decade ago, back in IBM I v6.1. Despite this, it’s still commonly in use at many IBM i Shops. Using SEU is painful — it does not have any support for *FREE RPG ILE nor any of the RPG %built-in-functions that added with every new release. SEU is no better than a NOTEPAD editor, but also running with the limitations of a 5250 green screen.

What is the best ibm i rpg code editor in 2021? 3

If you open modern RPG ILE Code denoted by **FREE on the first line, SEU will spit out errors throughout the code because it does not recognize modern RPG code layout.



Legacy style code editing used by any programmer with grey hair or that came from older System38, AS400, iSeries machines



Unsupported and out of date

Standard terminal mode interface

Can only view page of code at a time

No DO/UNDO functions

The list goes on


Ibm rdi rational developer

IBM Rational Developer for IBM i (RDi)

Rational Developer for i is the official RPG development tool, it’s Very good. Very extensive. Very expensive.

IBM® Rational® Developer for i is IBM’s code editor for IBM i software development. RDi provides an integrated development environment (IDE) to create, maintain and modernize IBM i applications. It integrates developer tools such as search, edit, build, analysis, refactoring capabilities and code debug. Built on the Eclipse framework for faster, easier application development and modernization.

IBM releases frequent language enhancements to RPG, so moving to RDi is the only was to stay current with IBM i syntax changes and rapid code development.

What is the best ibm i rpg code editor in 2021? 4

Rational Developer for i is my editor choice. It’s has some really neat functions like refactor, convert code to sub procedure, the ability to hunt and find variables in the program source code and seeing where values are changed (even subfields of data structures) make this stand head and shoulders above the primitive code editors like SEU.



The IBM i Code Editor fully support by IBM

Regular updates as new opcodes are added to code

Powerful features which boost rapid application development

Compile and Debug Functions

Easy to use



Slow to load

Heavy Application with big install

Visual Studio Code

Note – this is not Visual Studio. This is a separate editor from Microsoft.

What is the best ibm i rpg code editor in 2021? 5

Visual Studio Code is lightweight and it’s fast. It feels like NOTEPAD++ on steroids. VS Code is free, open source and cross-platform editor means it runs on Windows, Linux and macOS. It’s plugin function means you can work on all kinds of languages all within the same IDE – it supports almost all the major programming language. It supports IBM i (RPGLE, DDS, SQL, etc) , Python, JavaScript, HTML, CSS, TypeScript, C++, Java, PHP, Go, C#, PHP, SQL, Ruby, Objective-C and much more. Visual Studio Code has a complete Git integration, so if using GIT for version control of your RPG code is on the to-do list — this could be the one for you!

Just like Orion and Notepad++, by default source code is stored in the IFS within Visual Studio Code. This technique is being adopted across the IBM i community and is, almost definitely, the future of source code storage. Visual Studio Code is growing in popularity. But it’s not limited to IFS – various plugins can extend VS CODE’s abilities and will allow access to native IBM i Database structure of LIBS and Files (SCHEMAS and TABLES to you SQL propeller heads)

The nice thing is that as Visual Studio Code user base grows – so does the list of plugins that extend VSC into new arenas. We can install a number of RPG plugins to look at:

Visual Studio Code – IBM i Languages Syntax Checking

Somewhat decent syntax highlighting for IBMi languages such as RPG, CL, DDS, MI, and RPGLE fixed/free.

The plugin author says this uses a regex to add syntax support for the main IBM i Languages:

Pretty much all I did was crawl through various IBM documentation on my lunch breaks and throw some regular expressions in here when I got the chance. The regex I made probably isn’t too efficient and it does mess up sometimes, but I think it works for like 90% of cases I’ve come across.

NOTE: This plugin was derived from the following RPG LANGUAGE PLUGIN from Niels Liisberg. So, choose one or the other IBM i Languages Syntax Checking is my favourite.

Visual Studio Code – RPG Language Plugin

This offers RPG source highlighting and syntax checking for ILE FREE RPG from version 7.1 and above. You can follow this project at https://github.com/NielsLiisberg/RPG-for-VSCode

What is the best ibm i rpg code editor in 2021? 12

Visual Studio Code – ILEDITOR 2 code-for-ibmi 

This is the best IBM i Software Development plugin for Visual Studio code. In my Humble opinion of course! (or IMHO as the cool kids type it)


Maintain your RPGLE, CL, COBOL, C/CPP on IBM i right from Visual Studio Code. Simple, easy to use with some nice features:

  • Member browser and editor
  • IFS Browser and editor
  • Object browser
  • Settings: Compilation, library list, etc,
  • Error lists show up in Problems automatically

NOTE: In order to use extension, the SSH Daemon must be started on IBM i (Licensed program 5733-SC1 provides SSH support. STRTCPSVR *SSHD starts the daemon). Install from VS Code You can find the extension in the VS Code Marketplace! More detailed documentation is available here



Industry Standard Code Editor

Growing list of slick plugins for VS Code

Fast and Easy to use on any PC, Linux or Mac machine

ILEDITOR2 – allows LIB/FILE as well as IFS source editing

You can find the ILEDITOR 2 extension in the VS Code Marketplace!


Not Much!

This supports RPG well, but it’s not a native RPG focused code editor

Debug functions are missing for RPGLE (at time of writing but I’m sure will appear soon)



This is a great low cost alternative to RDi. For €99 per year, you get a decent competitor to RDi. Missing some features but it’s a good alternative considering the price.

One other benefit is that it has a free version for users of PUB400 (MiWorkplace – Editor for IBM i) PUB400 offers a free alternative to RDi?? Yes, you read that correctly. It can be used without any charge. You get a fully functional version of MiWorkplace with a preconfigured connection to the one and only public IBM i server pub400.com. There are no excuses anymore why you can’t learn something new on IBM i.



Since being bought by REMAIN Software it has new features and support

Light interface

Easy to use



Since being bought by REMAIN Software the price has increased from $39 to $99 per year

Does not have a REFACTOR function


Orion is a simplified browser-based editor. IBM has ported this open-source editor to IBM i and included syntax highlighting for RPG, CL, COBOL, DDS, and UIM. Orion automatically saves your source as you make changes

If your source is in the IFS, you can use Orion. Orion is an open source browser based editor that has been included in 5733OPS option 8. It is still a little lean, but may be a competitor to Notepad++ depending on your circumstances. Orion is a simplified browser-based editor. IBM has ported this open-source editor to IBM i and included syntax highlighting for RPG, CL, COBOL, DDS, and UIM.

Web ide

Orion automatically saves your source as you make changes, a feature I like. It also has built in support for Git, which is also included in 5733-OPS.



Free – if you have 57330PS installed on your IBM i System

Supports GIT



Only supports IFS based source system

Browser based


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This is essentially a notepad editor, not an IDE (interactive development environment) but with its multi-tab layout and ability to extend functions with plugins it’s a struggling alternative to SEU.

There is a plugin for free-format RPG which extends notepad++ into the world of very basic RPG editing.


Another plugin giving you the ability to execute remote commands and compile.

What is the best ibm i rpg code editor in 2021? 14

The last time I look at these plugins they did not support *SRCPF, instead forcing you to use the *IFS for source code storage – which I like but may be a showstopper for you

What is the best ibm i #rpg code editor in 2021


NOTEPAD++ is a free code editor

It’s a terrific upgrade to your basic NOTEPAD editor

Extensible plugins for NOTEPAD++

What is the best ibm i #rpg code editor in 2021


Basic syntax checking

Upload/Download of source only works with IFS

Final Thoughts

Having to pay premium $$ for a program source code editor grinds my gears – nearly a thousand dollars for IBM’s offering and other premium products ranging from $99 to $350 per year is painful for us freelance developers. Come on IBM – Release a lightweight, desktop Free RPG Editor!?


HONORABLE MENTION – Deprecated RPG Code Editors

ILEditor V1

ILEditor was an editor for development of ILE applications on IBM i. ILEditor will support development with any ILE language, be it CL, RPG, COBOL, C or C++. Error listing and syntax highlighting is available for all ILE languages.

Websphere Development Tools – although its free it’s also very old, doesnt support new RPG code and replaced by RDi

RPG Next Gen – I really liked this and used it after WDSC and before moving to RDi. The author has moved to a commercial route, checked out it’s replacement (Mi Workplace)

  • Dear,

    I think you miss Cobos4i product based on Eclipse and will a lot of features around COBOL and RPG especially for the IBMi platform : native emulator, trafic player, RPG converter, application designer and generator (RPG lowcode) …

    We can exchange on this product if you want and give it a try.

  • Hello and thanks for recommending alternatives!

    At a first glance my impression is (RDi 9.6):
    RDi is a complicated tool.
    The Editor seems to be ok.
    But I broke my fingers to develop simple code and compile it.

    I know eclipse from java development. Therefore: I’m not absolutely old fashioned.

    The integrated emulation does not support system attention/request key (the thing with the underline on the bottom) – (or eclipse ignores it) –> Don’t can reach job menu as usual.

    I was not able to find where the CCSID is set for the emulation: No Umlauts are shown. Is this only for english speaking countries?
    CCSID on connection does not affect emulation.

    I only can open one Emulation in RSE and in PDM view.
    In normal environment I need many for developement, test and production. If necessary with different user profiles…

    This is very noteable: The inventor of 5250 emulation does not deliver a complete emulation.

    RSE connection:
    I can define a job description on the connection properties.
    But a compile will not be submitted. It is noted in the RDi log. But never a job is started on the IBM i.
    I can compile from the RDi without batch (defined in the conneciton properties). This works! This is nice for single sources. But what is about mass compile?

    It is not clear, why RDi is a good tool.

    But I will go on and test it more.

    The use case is the newest rpg ile free version that is not supported by PDM/SEU.
    The only reason why I try to use RDi.

    Hello COBOS4i: Are you better for DDS, CL, CLLE, RPG ILE free….?
    If yes, then hello COBOS4i and good bye RDi.


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