7zr file archiver with high compression ratio

 p7zip is the Unix command-line port of 7-Zip, a file archiver that
 handles the 7z format which features very high compression ratios.
 .
 p7zip provides:
  - /usr/bin/7zr
    a standalone minimal version of the 7-zip tool that only handles
    7z, LZMA and XZ archives. 7z compression is 30-50% better than ZIP
    compression.
  - /usr/bin/p7zip
    a gzip-like wrapper around 7zr.
 .
 p7zip can be used with popular compression interfaces (such as File
 Roller or Nautilus).
 .
 Another package, p7zip-full, provides 7z and 7za which support more
 compression formats.