IBM COBOL to Rust, Java,
or C++17. Exactly.
Deterministic transpilation. No AI. No heuristics. No guessing. Byte-for-byte behavioral parity — verified against the official GnuCOBOL federal test suite. Your business logic. Your ownership. Zero IBM dependency.
Not a claim.
A receipt.
Every program runs twice — once as the transpiled output, once as the GnuCOBOL reference. Their stdout is compared byte for byte. The results are public and reproducible on any machine with Docker.
Reproduce it yourself.
One command. Pulls a prebuilt image, compiles every Java program, runs each one, diffs against GnuCOBOL reference output. Completes in ~2 minutes. Reports PASS: 723 / FAIL: 0.
| Category | Count | Result |
|---|---|---|
| Rust byte-for-byte parity | 976 / 976 | 100% |
| MATCH (output identical) | 405 | ✓ |
| BOTH_EMPTY (silent — correct) | 439 | ✓ |
| COMPILE_FAIL_PASS (diagnostic) | 100 | ✓ |
| DIAG_OK (positive diagnostic) | 32 | ✓ |
| MISMATCH | 0 | — |
| BUILD_FAIL | 0 | — |
| RUN_ERROR | 0 | — |
| Java behavioral parity | 723 / 723 | 100% |
| C++17 parity | 1,607 / 1,607 | 100% |
| Unsafe blocks in Rust | 0 | — |
| AI in the loop | None | — |
Three targets.
One engine.
Ironclad, BOBO, and the C++17 target share the same deterministic transpilation core. Same COBOL input. Same parity standard. Different output language — your choice.
Maximum memory safety. Zero unsafe blocks. Compiler-enforced correctness. NSA and CISA recommended memory-safe language. Zero GC pauses. Highest security classification available.
976/976 parity · 0 unsafe blocksImmediate staffability. Broad talent pool. Pure JDK 11+, zero third-party dependencies. Static security audited — zero findings across eight categories. Docker-reproducible.
723/723 parity · 0 security findingsSystems-level performance. Full C++17 standard compliance. Zero external dependencies. For environments where Rust is not yet an option and Java performance is insufficient.
1,607/1,607 parityReal federal COBOL.
Not textbook examples.
Beyond the test suite, Ironclad has been applied to real production COBOL at federal scale — the programs that break every other tool on the market.
CMS Medicare Payment Pricers
The actual COBOL that calculates Medicare payment rates for dialysis centers, hospitals, hospice providers, and skilled nursing facilities across the United States. The most complex COBOL in existence — REDEFINES chains, COMP-3 packed decimal, 69 copybooks, OCCURS DEPENDING ON. Processed without error.
AWS CardDemo — CICS Credit Card Processing
Amazon's reference CICS/COBOL credit card processing system — the industry benchmark for mainframe modernization tools. 30 of 44 programs use EXEC CICS. Full DB2 with cursors and SQLCA. 75-copybook hierarchy with deep REDEFINES nesting. Full CICS context handled completely.
Send us one module.
We prove it works.
No commitment before demonstrated value. Send one non-critical COBOL module. We return the fully transpiled output. Your engineering team validates it. If it does not meet your standard, the conversation ends at zero cost.
Request a Demo
Tell me about your estate — the source language, roughly how many programs, and what you'd like to see proven. No customer data required. I'll get back to you quickly.