Krusader is an advanced twin-panel (commander-style) file-manager for KDE 3.x, but with many extras. It provides all the file-management features you could possibly want. It also features extensive archive handling, mounted filesystem support, FTP, an advanced search module, a text viewer/editor
... [More], directory synchronization, support for file content comparisons, powerful batch renaming, and much more. It supports the following archive formats: tar, zip, bzip2, gzip, rar, ace, arj, and rpm. It can also handle other KIOSlaves such as smb:// or fish://. [Less]
muCommander is a lightweight, cross-platform file manager featuring a Norton Commander style interface and running on any operating system with Java support (Mac OS X, Windows, Linux, *BSD, Solaris...).