OpenAI upgrades its model for COBOL, Fortran, and other legacy code

OpenAI says its latest model is now better at writing and migrating software in COBOL, Fortran, and Visual Basic. An estimated 800 billion lines of COBOL remain in production. That code powers systems at banks, government agencies, and large enterprises. What OpenAI announced OpenAI shared the update on X on October 19, 2026. The company said its newest model improvements help with building and migrating code in what it calls low-resource languages. In AI terms, “low-resource” describes a language with relatively little code for a model to learn from. OpenAI framed the work around two jobs. The first is helping teams understand business logic that was written decades ago. The second is preserving how existing systems behave while they get modernized. OpenAI is also asking developers and enterprise customers for input. It wants to hear which other languages or workflows could benefit from similar improvements. Why legacy code is so hard for AI COBOL has historically been a weak spot for coding models. Research benchmarks have shown low Pass@1 and compilation rates on COBOL tasks. Those rates have ranged from single digits to about 40%. Pass@1 measures how often a model gets a workin...