ZIP is the closest to an "industry standard" portable filesystem. It's directly comparable to Quake's PK3 format because that's all that PK3 was, a ZIP with a c

ZIP is the closest to an "industry standard" portable filesystem. It's directly comparable to Quake's PK3 format because that's all that PK3 was, a ZIP with a custom file extension. It's also what "powers" a wide range of portable filesystem in a single file tools such as DOCX and ODT and quite a few other modern Office and Office-adjacent file formats.