Things we would like to add for the OS interface and OS-related libraries (mostly from fperrad):

 * chmod(2) or similar interface (see TT#1322)
 * some means of accessing archive (tar) files (see TT#1598)
 * some means of generating compressed (gzip) files, for example a GzipHandle PMC which wraps zlib (see TT#1580)

The goal here is to reduce dependency on our system(3) wrapper, which is a portability liability.