PeaZip is an open source portable file archiver, released under LGPL for Windows and Linux.
It supports its native PEA archive format (featuring compression, splitting and flexible authenticated encryption and integrity check schemes) and other mainstream formats, with especial focus on handling open formats.
Full support: 7Z, 7Z-sfx, BZip2, GZip/TGZ, PAQ8F, PAQ8JD, PAQ8L, PEA, QUAD, split (.001), TAR, ZIP;
Browse/extract support: ACE, ARJ, CAB, CHM, CPIO, ISO, Java archives (JAR, EAR, WAR), Linux installers (DEB, PET/PUP, RPM, SLP), LHA, LZH, Open Office file types, PAK/PK3/PK4, RAR, Windows installers (NSIS, some MSI), WIM, XPI, Z/TZ.

USER INTERFACE:
PeaZip's UI aims giving aid to the user to:
edit, save and restore layout of archives;
save job definition, to be used in scripts or for learning purpose;
have a detailed job log after each operation.
Browsing and selective partial extraction and listing of 7z-supported archives is implemented with a navigational browser (featuring also an optional flat mode) and an advanced filtering mechanism allowing multiple inclusion and exclusion filters.
PeaZip's most used functions are also available from "SendTo" menu (and context menus under Linux), allowing to: send files to .7z, .pea and .zip archives, encrypt multiple files and folders (.pea encrypted archive, with optional two factor authentication), split files, extract, list or test multiple archives (even of different types) at once.
The interface is skinnable in colors, transparence and icons.