I was just wondering about the rational behind the format of gem
packages. It seems rather odd that the package is a tar of

  data.tar.gz
  metadata.gz

Why not just have the metadata stored in with the data and not worry
about double layers? The only advantage I can figure is that it is
possilble to extract the metadata without uncompressing the eniter
package. Okay, but can't a tar/gzip lib or tool do that anyway? Is
there some other reason?

Thanks,
T.