@Reiddragon @iska @lispi314 tarball of tarballs yeah. i think rpm were cpio archives in one version, and xar archives in a failed attempt to update the format.

xar was kind of interesting its like an xml file of the manifest and then a huge tarball no man's land where you can do whatever and the xml file just points you to the offset+length in the buffer. apple used it for a time.