IBM i 開発者向け！ VSCode拡張機能This article introduces VSCode extensions tailored for IBM i developers,…

IBM i, the operating system that traces its lineage back to the AS/400, continues to run business-critical workloads at thousands of organizations, yet the tooling many of its developers rely on has long felt disconnected from mainstream software development. This article surveys the growing ecosystem of Visual Studio Code extensions aimed at IBM i developers, and explains how they let teams write RPG, CL, and SQL against the platform while working inside a modern, widely adopted editor.

For decades, IBM i programming was done through green-screen utilities such as Source Entry Utility (SEU) and Programming Development Manager (PDM), accessed over a 5250 terminal session. IBM later offered Rational Developer for i (RDi), an Eclipse-based IDE that brought a graphical interface, syntax checking, and outline views. RDi remains capable and officially supported, but it is a commercial product with a look and feel that differs from the tools younger developers tend to know. Visual Studio Code, by contrast, is free, cross-platform, and familiar to a broad audience, which makes it an appealing on-ramp for teams trying to attract new talent or standardize on a single editor.

The centerpiece of this movement is the community-driven Code for IBM i extension. It connects to a remote IBM i partition over SSH and lets developers browse and edit source members in traditional source physical files, navigate the Integrated File System (IFS), and work with libraries, objects, and members through a graphical explorer. Compilation is handled by running the platform's native commands, so a developer can edit an RPGLE member in the editor and trigger a compile on the host, then read the resulting error listings without leaving VSCode. The extension is typically installed alongside companion pieces, and a bundle often referred to as the IBM i Development Pack groups several of them together to simplify setup.

Language support is a significant part of the appeal. Extensions provide syntax highlighting, content assist, and outline navigation for RPG, including modern free-format RPGLE, as well as CL and other IBM i languages. A separate Db2 for IBM i extension lets developers run SQL statements and stored procedures against the database and view results in a grid, which is useful given how tightly integrated Db2 for i is with the operating system. Some tooling also surfaces the output of the ILE compiler and static analysis so that errors appear inline, closer to the workflow developers expect from other languages.

These tools sit within a broader industry push to modernize IBM i development rather than replace the platform. IBM has promoted cloud-oriented offerings such as Merlin, which packages IBM i development and modernization tools in a container-based, browser-accessible environment. Third parties including ARCAD Software provide extensions and services for source management, refactoring, and DevOps pipelines on IBM i. Taken together, these efforts reflect a recognition that the code running on the platform is often decades old and valuable, and that improving the developer experience is one way to keep it maintainable as experienced RPG programmers retire.

Adopting VSCode for IBM i does carry prerequisites and caveats. The host system generally needs SSH enabled and appropriate open-source utilities installed, and administrators may need to grant the right authorities for compiling and object access. Teams accustomed to RDi will find that feature parity is not exact, and some advanced capabilities may still be easier in the commercial IDE. Because much of the VSCode tooling is open source and community maintained, the pace of updates and the breadth of support can vary, so evaluating stability for production workflows is prudent.

Even so, the direction appears clear. Bringing IBM i into an editor that also handles JavaScript, Python, and container tooling lowers the barrier for full-stack and hybrid teams, and it allows source to live in Git repositories alongside the rest of an organization's code. For shops weighing how to sustain long-lived RPG applications, extensions like Code for IBM i offer a low-cost way to test a more contemporary workflow without abandoning the underlying platform. Developers considering the move would likely benefit from trialing the Development Pack against a non-production partition first.