Setting Up RDi: Bringing Modern IDE Tooling to IBM i Development

Rational Developer for i, known almost universally as RDi, is the modern counterpart to PDM and SEU — an Eclipse-based IDE that brings syntax checking, code outline views, integrated source control, and a proper debugger to IBM i development. For developers coming from more mainstream programming ecosystems, it's the tool that makes IBM i feel like a contemporary development environment rather than a step back in time.

Getting started with RDi begins with establishing a connection to a specific IBM i system. That connection defines how RDi communicates with the system — which host to reach, which user profile to authenticate as, and which libraries and IFS locations to expose. Once configured, that connection becomes the gateway to everything else RDi offers.

The primary way developers navigate IBM i resources inside RDi is through the Remote Systems Explorer, commonly shortened to RSE. This view presents libraries, objects, and IFS folders in an expandable tree, much like a file explorer, letting developers browse and open source without needing to remember exact library and member names or IFS paths ahead of time.

Once a source member or IFS-based source file is open, RDi's editor provides capabilities SEU never had: real-time syntax checking that flags errors before compile time, an outline view that lets developers jump directly to a specific procedure or subroutine, and integrated debugging that steps through running code interactively rather than relying solely on job logs and dumps.

None of this makes PDM and SEU pointless to know — plenty of shops still rely on them — but for developers doing serious day-to-day RPG development, RDi is where the real productivity gains live. Faster navigation, earlier error detection, and a debugging experience that matches what developers expect from any modern IDE all add up to meaningfully faster development cycles.

Getting comfortable with RDi early pays off well beyond IBM i Platform Foundations. Every subsequent lesson in this course — from basic free-format syntax through advanced service program design — assumes a developer who can move confidently through RDi's connection setup, RSE navigation, and editor views.

This lesson is Lesson 5 of IBM i Platform Foundations in IBM i ILE RPG Mastery, preparing the development environment you'll rely on throughout the rest of the course.