OP here. A bit more context: I built this mainly for packaging cross-platform release artifacts where ISO compatibility gets tricky (Unicode filenames, files >4GB, and preserving UNIX permissions).

The app can create new images and also modify existing ISOs (add/replace/delete files, then rebuild). It supports ISO9660/Joliet/UDF/Rock Ridge so you can pick a compatibility set that matches your audience.

I’d love feedback on real-world edge cases to test: mounting behavior across OSes, Unicode normalization, deep paths/long filenames, large directory trees, etc.