IBM i Merlin
IBM i Merlin was IBM's browser-based development and modernization workbench for IBM i, built from IBM, Red Hat and ARCAD Software tools running in Red Hat OpenShift containers. It converted fixed-format RPG to free format, analyzed application impact and ran Git and Jenkins pipelines, and IBM withdrew it from marketing and service on October 7, 2025.
What Merlin did
Merlin was a workbench you opened in a web browser. Its job was to put IBM i application work on the same kind of tools other programming teams already used. One place to edit code, keep it in Git, build it and ship it.
Merlin was not an AI tool. It is worth knowing because it was IBM's answer to modernizing RPG, the Report Program Generator language, for three years before AI coding tools took over that job.
What it could do to your code
- Convert fixed-format RPG into free-format RPG, using an ARCAD tool IBM renamed Converter
- Show what one change would affect across a whole application, using ARCAD Observer
- Keep source code in Git instead of on the system alone
- Build and release through Jenkins pipelines
Which languages it handled
- RPG III and RPG IV
- COBOL
- CL, the IBM i Control Language
- DDS, or Data Description Specifications, which define files and screens
- SQL, the Structured Query Language
Merlin timeline
- May 2022IBM announces Merlin alongside IBM i 7.5. It needs IBM i 7.4 or 7.5 and runs in Red Hat OpenShift containers.
- Jun 14, 2024Merlin 2.0 ships with IBM i 7.5 TR4 and 7.4 TR10. The editor moves to Visual Studio Code, the Code for i plug-in is bundled in, and a Single Node OpenShift option shrinks what you have to run.
- Oct 7, 2025IBM withdraws Merlin 2.0 from marketing and service. Version 1.0 was already out of service.
- Mar 24, 2026IBM Bob 1.0.0 reaches general availability, so the AI coding tool IBM pointed Merlin customers toward is now shipping.
Dates from IBM product support pages and IT Jungle reporting.
Why did IBM drop Merlin?
It did not sell. Merlin asked an IBM i shop to stand up Red Hat OpenShift, a container system for running software in isolated boxes, mostly so developers could get a better editor. Most shops did not want that. At the same time Code for IBM i, a plug-in for Visual Studio Code that Liam Allan created in 2021, spread quickly and did the editing part with none of the setup.
IBM i chief technology officer Steve Will said the main reason was a more streamlined focus on where IBM was putting its development effort. IT Jungle wrote in 2024 that sales of Merlin had not broken any records, and in its 2025 review called the problem poor market timing against Visual Studio Code and Code for i.
What replaced it?
Merlin and the tools IBM pointed developers to instead
| IBM i Merlin | Code for IBM i | IBM Bob | |
|---|---|---|---|
| Form | Browser workbench in OpenShift containers | Visual Studio Code plug-in | AI coding agent built on Visual Studio Code |
| Available | May 2022 to October 7, 2025 | Created by Liam Allan in 2021, still in use | Generally available March 24, 2026 |
| AI built in | No | No | Yes |
Liam Allan created Code for IBM i in 2021 and joined IBM on July 1, 2022. He now works on Bob.
If you are reading old Merlin material, treat it as history. The modernization work it promised now happens in Visual Studio Code, with Code for IBM i for the editing and IBM Bob for the AI help.
Related Terms
IBM i
IBM's operating system for Power servers running traditional AS/400-lineage business applications, with Db2 for i built directly into the OS.
RPG
Report Program Generator, the primary business application programming language on IBM i and its AS/400 predecessors, still running the majority of production logic in most IBM i shops.
Free-Format RPG
A modern RPG coding style that drops the rigid column-based syntax of traditional fixed-format RPG in favor of freer, more readable statement syntax.
COBOL
A long-established business programming language still running production logic on IBM i and other legacy enterprise platforms alongside RPG.
Db2 for i
The relational database management system built into every IBM i operating system, tightly integrated with IBM i rather than a separately installed database product.
IBM Bob (Project Bob)
IBM's generally available AI coding agent for IBM i, built as a fork of Visual Studio Code and tuned for RPG, CL, DDS, and SQL. Reached GA on March 24, 2026; Bob 2.0 and the IBM i-specific Bob Premium Package for i shipped June 24, 2026.
watsonx Code Assistant for i
IBM's November 2025 preview announcement of an AI code assistant purpose-built for RPG on IBM i. The preview track was superseded by IBM Bob, which reached general availability in March 2026.
ARCAD MCP Server
A vendor-built Model Context Protocol server from ARCAD Software, launched in spring 2026, that exposes IBM i application metadata from ARCAD's own repository to AI coding tools including IBM Bob, Claude, and GitHub Copilot in VS Code. It is a separate product from IBM's own IBM i MCP Server.