Around 120,000 organizations still run business-critical applications on IBM i. Most intend to modernize, yet few execute — because the two options the industry markets most loudly don't fit the typical shop. Here is how refactoring, hosting, and recompilation actually compare.
| Refactor to Java | Rent & host the AS/400 | Recompile to native Linux | |
|---|---|---|---|
| Example | Blue Age and similar | Skytap, IBM Power Virtual Server | Infinite i |
| What it does | Convert RPG/COBOL into a new Java codebase | Rehost the existing IBM i environment in a cloud data center | Recompile your unchanged source to native Linux; move DB2/400 data to MySQL |
| Your application code | Rewritten — new language | Unchanged | Unchanged — recompiled, not rewritten |
| Off IBM Power? | Yes | No — still runs on IBM Power | Yes |
| Runs on | A new Java stack | IBM i on IBM Power (hosted) | Native Linux on AWS, Azure, or GCP |
| Typical timeline | 3+ years | Weeks (lift-and-shift) | 45–60 days |
| Cost profile | Millions; often $10M+ for large estates | Ongoing rental + IBM licensing | ~50% lower run cost; fixed-scope project |
| IBM licensing | Eliminated | Continues | Eliminated |
| Your RPG/COBOL team | Retrained or replaced for Java | Still required | Retained; standard Linux ops added |
| Business logic | Re-implemented (full regression risk) | Preserved | Preserved exactly |
| End state | Modern language — but new code to validate and own | Same stack, new location; platform lock-in and the skills crisis remain | Same applications, modern cloud infrastructure, off Power |
Produces a fully modern Java codebase. The trade-off is time and risk: multi-year programs, costs that can exceed $10M, and re-implementing decades of business rules — while moving your team to a new language. Best reserved for applications that genuinely need re-architecting.
Fast and low-disruption — your environment runs unchanged in a cloud data center. But it is still IBM i on IBM Power, with the same licensing and the same shrinking skills pool. You change the invoice, not the architecture.
The third path. Your unchanged RPG, COBOL, CL, and DDS are recompiled to native Linux on your cloud, with DB2/400 data moved to MySQL — typically in 45–60 days at roughly half the run cost, with your team and business logic intact. From there you can extend in Java, Python, or .NET against the very same logic.
Petro Peru moved their IBM i workload to AWS — off IBM hardware and IBM licenses, in under two months, for less than the cost of renting AS/400 capacity.
Want the full analysis? Read The Third Path, our white paper on the economics and risk of all three approaches.
Send us a representative slice of your RPG, COBOL, CL, and DDS. In about two weeks we will show it running on the cloud you choose — no license commitment until you have seen it work.
The core platform — recompile RPG, COBOL, CL, and DDS to native Linux on AWS, Azure, or GCP. 45–60 days. Half the cost of staying on Power.
Learn about Infinite i →An Infinite i add-on that turns IBM i 5250 green screens into modern web interfaces in any browser — automatically, with no rewrite.
Learn about Infinite Cloud →An Infinite i add-on that migrates DB2 for i (DB2/400) data to MySQL on AWS, Azure, or Google Cloud — with referential integrity fully preserved.
Learn about Infinite DataLink →An Infinite i add-on: a modern VS Code IDE for RPG & ILE COBOL — syntax highlighting, IntelliSense, Git, debugging, and AI assistance. In private beta; GA Q3 2026.
Learn about Infinite Studio →