Their COBOL stuff is positively modern when compared to the oldest part of the IRS stack, which is written in IBM 7074 assembly - that’s IBM’s pre-S/360 busines

Their COBOL stuff is positively modern when compared to the oldest part of the IRS stack, which is written in IBM 7074 assembly - that’s IBM’s pre-S/360 business mainframe line, from the early 1960s. It runs under an emulator on contemporary IBM mainframes. (I know IRS has been working on rewriting it all - the 7074 assembly, the 360/370 assembly, and the COBOL - in newer languages such as Java. I don’t know where they are up to with that, so I don’t know if they still have 7074 apps live today. But certainly they did as recently as 4-5 years ago.)