Getting Started with 7-ZIP Plugin
7-Zip plugin adds a support for 7-Zip archives. You can pack files and directories to 7-Zip archives; browse, test and unpack 7-Zip archives; and delete files and directories from 7-Zip archives. Files in 7-Zip archives can be encrypted.
See Archiver and Menu Extension sections in Using Plugins for a description of basic work with plugin archiver and menu extension.