As the author of PSPP, I'm currently rewriting it in Rust myself.

The hard part is figuring out SPSS file formats. They are complex and IBM does not document them. I spent years figuring them out--and I am still working on the format for graphs and charts. Maybe they are trivial for claude, but I doubt it, because there aren't very many examples of the formats easily available. I've collected tens of thousands of examples myself for my use, but I don't have permission to share them, so instead I've documented what I've learned.